One thing I do in my games, is that when i started playing MnB again I started to export my companions when i was more or less "done" with one game and was about to make a new one.
Then i import them into the new one, giving me quite a head start.
right now, all of my companions have at least 5 in trainer skill. after about 15 games in the last 2 months they have just about reached level ceiling, theyre all level 40-43 right now and training troops is much easier when you get that trainer xp every tick. troops dont get so much xp from battle as they should imo, but trainer skill seems to give them quite alot.
fighting a 40-band of sea raiders it says "2900 exp shared with party", whereas with 17 companions all having 5+ trainer skill i get something like "110,000 exp gained by party" every night - of course, thats each companion trainer level xp bonus * number of troops = total xp gained by party....but it seems a bit unbalanced. at least it does let me see more of the tier6-7 troops though.
i have a 109 day nord game going right now where i have 245 party size cap and out of that, have something like 7x ISa7, 11x IA7, 8x I7....ah right and i have about 20 tier6 manhunters. i have not yet held a fief so my roaming army is my only army.
ive played this game from the start quite aggressively, taking on merc contracts with 2 different lords at war back to back, but its been primarily my companions trainer skill that has gotten my troops leveled up. i started that game with my level 40-43 companions.
from time to time i start a fresh game without companions, starting totally new and weak but ive done that so many times i tend to much more enjoy getting a headstart and getting into the faction wars, intrigue, and more advanced features that this mod also makes available (which i didnt have before). grinding out exp in tournaments, training fields, and bandit hunting was fun the first year i played mnb, but hehe sorta gotten over it now.
im not suggesting you do what i do, but one thing i would suggest is that making an INT based character seems to work alot better especially due to the INT bonus when getting xp. the higher your INT, the higher bonus xp you get, meaning you can effectively level alot higher, and faster...and of course, INT gives you skillpoints, so you can max out trainer, and then hold onto some skill points for later pumping up your combat skills (which will be easier to pump up while you get a higher xp bonus from INT).
having a medic in your group, or preferably 2, is also very crucial. you dont want killed units. you want unconscious ones
some people have said that floris mod too much rewards INT builds, and some people dont like that, but you could try it and use it to your advantage a few times and see how you like it. personally i like it.