Having an elite army is not simple anyway, one mistake and you're gone (being cornered but a group of enemy army, a siege gone wrong, ect.). And is not easy to have one, it took 3 years in game to me to build an 100% of elite army. Of course, 1vs1 you win easy, but this was in warband too. A 1vs2 fight is just more difficult, once was a narrow victory, but most of my troups were just knocked out .
I agree with you about the mechanism for leveling the troups should be different (and not fight every bandit for xp, this is farming and is for wow, not for m&b), but the result i hope is the same, low elite units (1 to 3/4 tier), high low tier units.