Well, I used to play a lot of Battle for Wesnoth, and I thought it might be interesting to see the following concept in BattleMaster: particular unit types automatically fight better or worse in particular terrain types.
Rural: The baseline; all units are equally advantageous.
Townsland: All units are equally advantageous.
City: Infantry have a slight advantage over other unit types here.
Woodlands: Cavalry has a slight penalty here; archers fare better.
Mountains: Nearly every type of unit fares poorly here, particularly cavalry.
Badlands: Cavalry have a slight advantage here.
Stronghold: All units fight the same here due to the effects of the stronghold.
We can squabble over the particular details; the examples are just to give you an idea of what I'm saying... although it just occurred to me that we really don't have a big enough variety of terrains for this suggestion to be useful.
| Region Type | Archers | Infantry | Cavalry |
| Rural | No change | No change | Non-combat movement +2 |
| Townsland | Archers defending +1 attacking -1 | No change | Non-combat movement -1 |
| City or Stronghold | Archers defending +1 attacking -1 | No change | Non-combat movement -2 |
| Woodlands | Archers damage -2 | combat cohesion -1 | combat cohesion -2 Non-combat movement -1 |
| Mountains | No change | no change | no charge, Non-combat movement -3 |
| Badlands | no change | no change | Non-combat movement +1 |
In mountain regions,archerseveryone would be better if they can get a higher position.
What if cavalry had the option to fight dismounted? Cavalry commanders would have the ability to dismount their troops, turning them into regular infantry with the same stats for the rest of the turn. If they are dismounted, and any battles would occur at the following turn change, the unit would fight as infantry. Units would only be able to mount/dismount once every turn (or every full day). I'm not sure if there is a difference in troop payment costs between infantry and cavalry with the same stats, but if there is, dismounted cavalry would cost the same as mounted.
I don't like this idea, unless there came some sort of penalty to dismounted cavalry. The thought is that they are trained to fight mounted, and throughout history, there were the fairly uncommon exceptions to cavalry that could fight well on foot. In recent history, there was that one guy in the Battle of Gettysburg who held out on that hill (Gee, my Civil War history sucks so bear with me).
Furthermore, the armor might be slightly different, as horseback riders will generally not want too heavy armor. Sure you can have this changed, but what if we introduce the idea that archers can also do the same? Then we might as well not have any set unit types in the first place and just call them "soldiers" at the RC, for the troop leader to customize.
So the point is, generally, bad idea to have convertibles unless this was balanced out some other way. Also it would mean we can't just define unit type variables by infantry, archers, mixed infantry, cavalry, special forces, peasants, daimons, monsters, undead, whatever else, but need a further special indicator for which infantry are obligate infantry and which are converted from cavalry.
Cavalry hate to fight dismounted, and typically do so poorly.
I suppose that since all of our battlefields are "wide open", with no tents/carts/huts in the way, that Cavalry might as well be allowed to charge.
French knights often fought dismounted
All I see for all these changes is a lot of time spent coding, potential for a lot of bugs, likely poor balancing, and all this for very little gameplay improvement.
Would this really make things more fun, or would this just make avoidance a more common tactic whenver marshals see that certain regions are not fit for their unit types, so it'd be better for them to retreat and perhaps fight elsewhere.
Most likely if a realm is smart enough to appoint good marshals who can micro terrain and movements, then there would be a lot more moving around instead of actual battles. Timing would be a lot more important, and that might, but would not necessarily, lead to more pressure on people to be prompt in reacting to orders.
I can't see anything like this being added to the game. The combat system is intentionally abstracted away. As Chenier says, this would be an extensive coding effort for what would be very little return.