Nah horse requirment is step in good irection.
We should also need basic/regular/elite weapon/armor sets to pgrade troops
And where do you draw the line? "Oh my battanian warriors have upgraded to elite battanian warriors and used up my elite armor units - which i'd reserved for my vladian knights to use - but they're savages all running around bare chested!"
And if you don't make upgrades consistent across empires (as my facetious example above does) then you get
massive economic imbalances.
Unlike horses, which are a primary resource, equipment would need to be a secondary resource - and so should be produced by cities or workshops as part of the economic simulation (if its not using the economic simulation to be produced ... what is even the point in having it? So It would have to use the Econ sim).
This will rapidly lead to snowballing if any one empire can take one extra city and increase their equipment supply non-linearly which will have big price swings, or more snowballing if its units don't need more expensive armor types to upgrade and be more effective. This goes against what the last string of patches have tried to avoid, making that a bad idea for empire balance. In scientific terms this would be called a cascading (or cascade-prone) simulation, when a
complex system breaks down due to a
simple change (one city/node changing hands and shocking equipment supply leading to a crash/imbalance, and/or snowball in this case).
There's also something to be said for coding the AI to actually gather these things up to upgrade their own troops (do AIs even upgrade troops?) otherwise in late-game their effectiveness will fall off sharply vs the player.
If they
can upgrade, I actually wonder if the horse requirement is part of the reason why the Aserai (which have some great horse units) routinely get stomped in every game I've played, like are their generals carrying enough horses around to upgrade properly?
