You can only solo 50+ Ember with polearm , not bow. You barely get 100 arrows and you can't 1 shot them on day 1. However, this is not the point we are arguing. Why do you think a group of 50 to 100 men that is led by veteran soldiers will chase a horse archer on foot without any strategy if they are not stupid ? Taking advantage of other's insane stupidity is indeed an exploit. I don't want to talk about anything about renown, it is irrelevant to the topic and it's not my issue.
About T6 troops. You can get them eventually when you are not at war, but you can't just walk away to train troops when you are fighting more than 1 factions. Our advantages are pretty much based on our T6 troops vs useless footmen or light cavalry. I would like to see how can you kill hundreds of Fians when you are outnumbered then you can talk about giving AI more elite troops.
Taking out high tier ones is not simple at all. You have to trade troops with your companions several times in order to join a siege battle, and you gotta make sure the enemy army won't come to fight you while you are establishing siege camp without high tier troops. It's quite a bit work and luck.
The economy issue is kind of annoying but it did not bother me too much on my gameplay. I don't care how much denar the lords have, but they can't recruit tier 6 troops directly for free.
you reminded me of a interesting detail:
it is totally possible to sit without doing nothing in-game, but that requires indirect micro-management of your realm's economy + policies.
my findings are quite intriguing, and show a lot of "cheese" TW uses to create virtual difficulty.
So, 1st of all, never let a clan own more than 3 fiefs at once - ideally the max should be 2. - why? field partying + clan member numbers. If a "oh my lOrD" holds 5 fiefs with a 4 member clan - 1 fief will be without governor at all times - than the AI will RNG if it fields it's extra parties or not, often it'll opt to keep 3 memebrs as governors and field a single party - if the party gets captured, they will send a governor to start a new one or simply remain out of the field.
this means that they'll be effectively as trash as a companion starter vassal at level 2 clan.
for that we need to have control over fief distribution, which we don't unless gaming the disgusting voting system TW has shoehorned on us by always keeping all our fiefs at the borders (which will spam your screen with incessant raiding).
Past that, you must actually understand what fiefs you are giving your vassals and their economical potential. Vlandia has 2 trash castles with a single bound village (literally, we'd gain more from demolishing these castles than with what they offer economically for us or vassals)
These 2 must either be a secondary fief clans holding a town, or these clans will be pathetically weak. This same logic applies to other fiefs which requires us to observe their villages productions.
Horse villages can be more profitable than 2 village towns - so the optimal choice's to have vassals that hold castles with said villages only owning them and nothing else.
ideally we'll have a absolute distribution where all clans own 1 economically strong fief, or 2 average fiefs at all times. Than through policies we can strengthen their building potential, profits and influence incomes - that's achieved with high loyalty, high security, "castle charters" and avoiding policies that cause loss of income - this means sacrificing king power-ups and some of the good policies for defensive strategy (like cantons and similars) - after that you can simply let the AI do it's thing and watch. It won't give optimal results under optimal time-frames, but the AI will eventually snowball your realm and do everything on it's own. - the only intervention will be from you cancelling wars so the AI properly focuses on targets.
The optimal choice is to give t5+ clans the most profitable fiefs while keeping the lower tier clans with less income power that because the higher clans can field up to 4 parties at once.
the reasons behind all of this shenanigan is because AI will have exceptional armies if you let them get rich, and not only that, they'll also holster biffy higher tier reserves in their garrisons, so even when defeated they'll basically respawn with decent troops. - I just wanted to highlight this because if you manage your kingdom well, AI will field decent troops and you won't suffer from having to deal with peasant armies in your own faction.