Contents: more speculative proposals. Would probably take several posts to hash out details.
Last post, I asked what spells in the mid-levels look like in a system that took that shift to wilderness very seriously. This is really a special-case of a more general question:
What would wilderness-appropriate mid-level abilities look like for all classes in a system that took that shift seriously?
In the low levels in the dungeon, the fighter fights, the thief gathers intel, opens paths to treasure, and occasionally one-shots things with backstab, cleric spells make everything a little easier and interact with the resource game, and mage spells straight-solve problems.
If we went hard on wilderness, what sort of abilities would we want mid-level thieves and fighters to have?
Thieves are probably the easy one. Gathering information about the environment without attracting random encounters is just as important in the wilderness as in the dungeon. The explorer's mechanics for evading random encounters make sense, as well as extra stuff for exploring hexes more quickly and more efficiently, locating and evading "wilderness traps" like crevasses, mudslides, etc. I've been thinking about walking back my position on "don't show them the map" - show them a little of the map. Hexes that have been entered but aren't yet "explored" and mapped are slower and more dangerous to move through (and, if maintaining a map for the players, have their terrain shown but greyed out). Exploration takes time and can discover lairs and features. So then you tie thief abilities to that hex exploration mechanic. On the "opening treasure" side of things, you might have mechanics like ACKS' treasure-hunting and smuggling hijinks - figuring out where treasure is located and getting more out of the treasure you find by evading taxes.
The fighter's in a funny position. The +1 morale at 5th level sends a very clear message - the fighter's signature mid-level schtick is mercenaries. But actually running wilderness combats where you have a bunch of mercs (especially the sort of ragtag "two crossbowmen, a slinger, three light infantry, two heavy infantry, and one light cavalryman" mercs you see at low wilderness level) is generally a rough experience. Setting up reasonable, actionable outdoor terrain for a squad-scale fight between a goblin warband and a player warband in a way that seems fair to players and doesn't consume a huge amount of time is not an easy thing (and this perception of wilderness fights as high-risk and very susceptible to either short-notice variations in terrain or long-slog tactical combat is, I think, part of why my players historically dislike them). So I'm wondering if that's the wrong way to go about it, whether loosely-zoned wilderness combat would serve better, with mercenary troops and demihuman gangs "pinning" each other (in much the way that combatants in personal combat become "engaged"), doing some simplified resolution on their fights, and going into finer detail on the actions of the PCs against enemy heroes (and PC-engaged gangs). Slightly higher detail than the Domains at War: Campaigns battle system, but lower detail than the Domains at War: Battles one. There's probably some combat system that fits these parameters in Axioms somewhere...
And then for those single-monster fights that mercenaries aren't really supposed to help you with (make trivial by sheer volume of crossbow fire), maybe an answer is a morale penalty when facing big monsters. Wait, I'm repeating myself. Fighter morale bonus then helps make mercenaries slightly more effective against monsters, but might not fully eliminate the penalty (-2 sounds like a good starting point).
Another reasonable wilderness-tier ability for fighters would be something that helps them recruit mercenaries more quickly. Name-level's "free followers!" has the right idea, but it's too little too late. I've been kicking around a more structured system for downtime, and something as simple as "roll one mercenary type per downtime (roughly two weeks) in a market, without having to pay recruiting costs or spend any actual time" would probably be a good start. Literal free units ("companion cavalry" or "retinue") that replenish themselves are a nice option too, though. And a barbarian "Call Horde" (or Paladin "Call for aid from knightly order", scaling up to "Call Crusade") ability is too much fun to dismiss, though maybe more of a name-level feature. Manual of Arms to upgrade your mercs makes sense too - provided a simple way of tracking mercenary XP, maybe giving your mercs +10% would be nice.
... maybe mercenary squads should compete for henchman slots. You take the "spokesman" for the unit as an effective henchman, and then they're personal retinue, with maximum retinue unit size scaling with level, just as ability to command large units does (3rd level -> squad scale, 5th level -> platoon scale, 7th level -> company scale, and on up). The spokesmerc is assumed to be running a hench-tree below himself, which is a full-time job. He takes care of wrangling quartermasters and supplies and presents you with the bill, acts as a lieutenant in mass combat, and absolutely will not follow you into dungeons, no sir, he needs to keep these idiots from starting fights with the locals or poking the wildlife for fun. Retinue squads will go with you on wilderness adventures (and earn XP, with bonuses from Manual of Arms), whereas non-retinue mercenaries can only be used on military campaign with a clear domain-scale target, or as garrison. And then we can ban hench-trees outside of military command structures to simplify my life, and any recruiting bonus that fighters get helps refill the ranks of their retinues. If you like, can send a henchman to a market to gather mercs and become a known-loyal spokesmerc and retinue leader. Upgrading a retinue unit to the next size requires both sufficient level and time in market to expand its ranks.
(Probably some room for using henchman slots ("direct reports"?) for other classes' wilderness-level stuff too; thief gangs / cells, cleric congregations, wizard lab-rats, a pirate-assassin variant with ships' crews, and then in domain level stewards for one's domains. Concern: CHA was already a good stat, does linking it to literally every class' wilderness-and-domain game make it just ridiculous?)
... Heck, you could even relate retinues to domain-founding. Build up a big retinue, clear some land, and then grant it to them / "settle" them there, ending up with about one family per mercenary (camp followers, the girl back home, relatives who hear they've got land now and migrate) and a trained militia. And your spokesmerc becomes the steward. I like having domains be mostly-static, but if I had to deal with domain founding, this seems like an interesting way to do it. Similar economics to the "subject tribes" I discussed here.
Anyway, mercenaries as the fighter's central wilderness mechanic also suggests some ideas for cleric. Spells to mitigate mercenary damage in mass combat make a lot of sense; attrition in the wilderness is often through mercenary bodycount, analogous to the fighter's HP being ground down. I feel like morale-boosting spells or abilities also make sense for the cleric when used on troops of the same faith. Divine spells providing improvements to exploration and evasion also follow naturally (much like Find Traps). Some abilities in support of retinues of either holy warriors or fanatical peasants would also be entertaining (and makes sense with Fighting 1 - some fighting stuff, but not as much as Fighting 2).
As for the hybrid classes - assassin's wilderness game probably looks a lot like thief's. Bladedancer is like cleric but more focused on offense; maybe they should get more of the +mercenary morale spells, while cleric focuses on keeping mercenaries patched up between fights? Mass Swift Sword? Bard's wilderness game probably looks a lot like the fighter's, but less Manual of Arms and more Inspire Courage.
Explorer is the tricky one, because the whole class is built around the wilderness game. It does exploration the best, but also gets the fighter morale bonus. Perhaps a reasonable compromise is to give them similar morale and recruiting abilities to fighters, but only for light troops (light infantry, archers, and light cavalry). And then in comparison to the thief, they still don't have the treasure-related capabilities. Assassin is the one who comes away with the short end of the stick under that proposal, and I'm not really sure what to do about that. Abilities supporting plant-based poison use are a natural addition, I suppose. I feel like assassin's core gameplay in wilderness levels should be "go find beastman chieftains, shamans, and witchdoctors, and murder them", and poison supports that. So would something like Tracking or bonuses to interrogating captured beastmen; differentiating the assassin's "exploration" abilities from the thief's, by the focus on finding and killing things. They achieve similar results (getting you to the lair), but with different flavors. Likewise, could differentiate explorer and thief "exploration" abilities by giving explorer stuff focused on actually exploring and traversing hexes, with thief instead specializing in encounter evasion.
I have the nasty feeling I'm embarking down Fantasy Heartbreaker Lane. Call it A/X, Adventurer / Hexplorer, with a design ethos of "take ACKS' core rules and add slick, usable abstractions for wilderness (and maybe eventually domain) level play, grounded in ACKS' economic assumptions but with more focus on gameplay than simulation."