Glad to see I'm not the only one who was a little bothered by buildings leveling ^^. Though I do not doubt that in a long-drawn hard game, your units will die in great enough numbers that training new troops will level your buildings to the max, for milder games, or situations where you switch from mostly using a type of unit to using another type, the leveling system can get a little frustrating. Most of all, I think it encourages players recruiting units just to send them to their deaths until they get the better units they wanted to make, which I find strategically/economically nonsensical, and above all very contradictory with how good factions should work and are depicted in both books and movies : people caring for the lost lives of their soldiers.
As such, and considering BfME II had this system to decommission unwanted troops, I too believe that it could be worthwhile to look for a better way to deal with extra troops and building leveling.
There are a few lacking ways I can envision to deal with that :
- Allow the player an option in the buildings to purchase his way to the next level, as in BfME II, which in my opinion isn't a good idea (and that's most likely why it was removed ^^).
- Give, to all factions, access to a spell that can instantly level one or several buildings. It seems a more satisfactory way of doing things, but would take up a spell slot, which is sad ^^.
- Give passive exp. earnings to buildings, so that when getting towards late-game, even mostly unused buildings could grant access to their better units ; it feels a little lackluster though ^^.
And the way I would like to suggest, if ever it isn't too hard to implement, as I believe it deals with both superfluous troops and buildings exp. and goes somewhat the same way as the op's suggestion :
Allow us to decommission unwanted troops for a small amount of exp. (rather than resources, like in BfME II). I can however see more than one way of doing it :
- The units could be decommissioned at any appropriate building (a unit recruitment building), granting it an instant small amount of exp. While it does sound very simple, I believe it may require to give that ability to each and every concerned building and wouldn't be a very efficient way of doing it. That way though, exp. granted could be proportional to exp. earned by that unit on the field of battle, and this ability could be restricted : footmen to footmen buildings etc.
- As in BfME II, the units could only be decommissioned at the citadel, and doing so would temporarily unlock a power of the citadel that grants some exp. to the chosen building (out of the citadel's building plots, not the outside ones). If at all feasible, that way seems more elegant, because it would allow to force a cooldown on that ability, preventing the player to instantly level a new building from scratch to max
At any rate, again if it's feasible, I believe such a method can kill many birds with one small stone :
- get rid of unwanted units
- allow for an additional way to level buildings
- incite player to care for their units, even when planning to replace them with more powerful variants
- give a feeling of continuity between weaker start-game units that still served you well, and stronger units you'll need later, without using an upgrade system that would, in my opinion, be unnecessarily heavy to implement and use
- make a nice impression that veterans who survived the battles are allowed to rest, while becoming instructors to train better units
- allow for faction specific mechanics :
- Gondor, which heavily arms his soldiers, could get in addition to the exp. a small discount on the next unit produced in the building that was targeted (as if the equipment was passed over)
- Rohan, which relies on conscript peasants, could see the production time of the next battalion reduced, due to old soldiers helping train the new ones ; or farm productivity slightly increase for a short period of time, due to the decommissioned men returning to the fields
- The idea doesn't apply so well to evil factions, especially Mordor, as they rather rely on troops mostly thought of as expandable, but through the same mechanics, orcs could be fed to the Troll cage to speed Troll production or reduce cost or some other unique system.