I was thinking you had a lack of crowns because auxiliaries usually don’t really pose a threat when you wear mail shirts or better.
At day 20 your company should wear at least worn mail shirts, maybe a few mail hauberks if you did well or have cheap armorers.
And yeah, misjudging enemies happens a lot. Especially if you’re new to the game, but you will learn that with time.
Battle Brothers has a very steep learning curve but I also find it rewarding. As for losing not being fun, I totally understand that.
I usually try to do perfect runs and not lose any brothers but sometimes it’s just inevitable. Especially in the early game when your defenses are still lacking. I find that I lose most of my brothers in the first 15 days, then not anymore.
Basically, once you get heavy armor (200+) and battle forged perk + underdog your brothers will be almost invincible. Orc weapons, 2-handers and such will still be dangerous but you can practically farm raiders without any risk.
Honestly, 20 tries will be more than enough for you to get competent on Veteran difficulty. Usually having a good map is the most important thing IMO.
I am currently playing on 9840c3 map seed. You start out with really decent companions, the only downside is that there is just one hunting cabin, so getting good ranged brothers can be a bit of a pain.
Still, the map has lots of plains and good trade routes in the south for an easy early game. I hope you don’t get discouraged as it is definitely possible to “not lose” :).