Here's my best and time-tested advice for the early game:
1. Raise your own level first.
2. Equip yourself often with the best gear that you can find or afford.
3. Hire eight compatible heroes.
4. Sleep daily after your party morale reaches excellent.
5. Forget about recruiting anyone else.
6. Do not attack farmers, caravans, or siege castles, towns, or raid villages.
I start solo by fighting looter groups until I get to level 5 or 6 or bored. I equip my avatar with loot and sell the rest. After every battle I compare my equipment with the loot and upgrade when possible. I also go to towns often to buy upgrades and replenish food as needed.
Then I travel to the various towns cautiously to find heroes in taverns. Like you, kings, and lords, they never die. I'm not talking about the mercenaries like caravan guards and the like but rather the ones with names like Alayen, Ymira, Borcha, and such. Your losses will only be wounds which means that they will be alive to fight another day and increase in levels eventually.
I avoid recruiting prisoners, villagers, or anyone who isn't a hero early in the game. The reason is that big armies scare away the smaller groups. Unless your map speed is sufficient to catch them, you'll find yourself chasing enemies for days and that lowers morale, consumes food, and costs wages during the chase. Someone in the party needs high path-finding (increased map speed) and one needs high spotting (to see distant enemies). The same hero can have both but that leaves fewer points for other skills.
Once I have morale up to excellent, it's time to sleep and allow more bandit and deserter parties to spawn. I check my food supply before sleeping.
Until I become a vassal for a king or decide to become a rebel, I do not attack farmers or caravans. The same applies to sieging castles and towns. I don't raid villages anymore but used to. I've learned that any village could become mine someday and they will never forget what I did to them.
Once my troops and myself are sufficiently high in level then I will recruit from villages. I may also do so if the enemy groups are much bigger than my troops can handle.
If you hire from your prisoner pool, do it early in the day and do your best to fight often and raise them one level so that they don't run away during the night. Only non-upgraded prisoners run away, at least in my experience.