let me hammer it real quick
1) there is not a single unit in the game that survives a hit of let say a javelin with 132 base damage. Enemy lords fall first, well at least in my case, because i hunt them down. It really doesn't matter how many hp they have. No difference. At all.
2) there is no such thing as AI fight well in the battle, AI does suck in this game (well at least for now, i hope). Lords, companions, all of them are equally worthless. Bannerlord is not a Warband, quality and quantity of troops does matter, but a named NPC is just yet just another unit with no special skills, abilities and value.
3) Simulations are in some particualar, so that if you ambush a group of looters with your 350+ party there is a really good chance that T6 units will die in some numbers. How many hp lords have in simaltions hardly matters. It does matter, but not as much as you assume it does.
Your suggestion is simply irrelevant. Because it has no impact on how things are in this game.