No, I am not missing the point. These are just not really viable choices.
You are missing the point. I'm not dealing with the issues as their own isolated incidents.
Again, if you make it take longer to reach the highest tiers then the consequence will most likely be that only low attrition units, such as archers, survive long enough to reach there. So it wouldnt matter if e.g. a similar tier high level infantry was equally as good as an archer. You wouldnt have many of the former, but you could potentially have plenty of the latter. So, its not an option to tweak this!
If you make it take longer to get the higher tier troops as it's one isolated solution, yes, archers would predominantly survive more (in scenarios where player recruits equal amounts all the time and splits the upgrades equal all the time; and also not adjusting their battle tactics too). I'm saying, of the 3 'options' (time/money/quality) to improve a unit, pick 2 to improve/buff/keep; the remaining should counterbalance it.
Practically no-one wants high quality units to be "bad". So... its not an option to tweak that either!
I did not say to make them 'bad', if you/us want to make the top tier units/armor more effective than they currently are (relatively ok spot atm), either make them cost more or take longer to get. I'm not for making them steamroll even further than they currently are without adjusting the other aspects to counterbalance. You want OP troops, don't make them both cheap and also quick to replenish; just dumbing down the game's 'complexities' even further.
Cost. You cant tweak it high enough that it would matter for an experiences player. So, it would only affect less experienced player who, for some reason, already have some financial challenges. So... not an option either!
It would for experienced players - if they have a few garrisons, own/companion parties, caravans, etc...those minor % increments to the cost-efficacy of the units (be it in the upgrade cost, maintenance/upkeep cost, recruit cost, food consumption cost, morale cost, etc...) can make the difference of netting $5k denar after to maybe $2k. Or how much food variety you should keep for morale, or how many horses to upkeep or keep in inventory, etc...Maybe add a few more actual conscious decisions for them to 'balance' whether they should upgrade certain troops or not, or go for different builds TBD on that cost-efficacy and the route the player ended going or RPing. As it is currently, you can just upgrade all with no thought or no impact on your playstyle.
So for less experienced players that currently already struggle with money in the game, it
should be challenging and not easy to get a 150+ stack of Elite Cataphracts/Fians. You steamroll all enemies and it completely accelerates the snowball effect of the player power way too quickly/easily than it is already. It should feel challenging achieving and maintaining a 150+ stack of elites.
Especially if that does require making sure your workshops are efficient/capped, caravans/perks are somewhat optimal, fiefs owned/management decisions impactful. As it is with the above, it is just clicking a few buttons, but there's no 'management' or 'puzzle-like' aspect to any of it.
In short. I sincerely doubt TW would go down that road. This just aint gonna fly. Mods perhaps.
Again, don't look at those 3 aspects as individual issues without adjusting the rest, as they should all counter/balance with and against each other. Or you end up getting an inflated player power scaling; more so than it already is (and always will) for players.