Most of the hideouts I don't have too much trouble with (they can still be extremely hard from time to time) except for the FOREST BANDITS GOD DAMN IT WHAT THE HELL WERE THEY THINKING. During my first playthrough I came across a hideout like you had described with 50+ bandits inside of it and I wanted it gone because it kept spewing out bandits that just reeked havoc on my villagers time and time again. At this stage of the game I thought it was all proportional. Like, okay, they have 50 in there maybe I should approach the camp with 100 troops instead of my usual group of 40 or so and then maybe 25 of them will get in there, thinking it would scale. So I load up from my garrison my most expensive badass troops I've been nurturing from the start of the game only to get killed nearly instantly because it was occupied by FOREST BANDITS GOD DAMN IT WHAT THE HELL WERE THEY THINKING. I got captured and I lost all of my troops and inventory because of that. And my guy still only took like 9 people in there....
Yes, I hate Forest Bandits in general. I think armour has too little effect in the game for my liking, missiles are both too accurate and too powerful, and on top of that the Forest Bandits have strong armour (at least it looks strong, I haven't checked the stats). It would be better too if we had proper stealth in the game- the enemy don't seem to notice you until you get close, but I think they become aware of you even if they are not facing you. It is, unless I'm mistaken, all about distance, which obviously is very simplistic. I don't think line of sight awareness is a thing for the AI and probably never needed to be in normal battles, but I think it would greatly enhance these special missions like hideout raids. Then you could have patrolling guards, a bit of randomistaion to where they spawn to keep you on edge and give you more chance of killing them off one by one with careful play. That would be more rewarding than desperately trying to survive the onslaught when half a dozen bandits 'see' you near the start and one shot half your team with javelins from 40 yards!
I do really like the Desert Bandit hideout though; tough but not impossible, and entertaining.
I've found that hideout can be done, on occasion even solo, if there weren't a final encounter. Since my character's backstory was mostly caravan and a scout, it was pretty easy for me to snipe off enemies (provided that they are not ****ing mountain machinegun arrow bandits) because they are all scattered about the map, some patrol alone, some sitting on a bench somewhere. There are the odd cases where 3-4 bandits all sit around a bonefire somewhere, and that was when I had to use my soldiers to block their path.
Problem is that my melee skill is just not enough to deal with the bandit boss in a duel, and if I got **** tier troops that final encounter can be impossible.
For the duel, being not great at quick melee fighting (though my pride and habit make me play on hardest settings
), having a character with poor stats and it being dark...I stopped picking the duel after 3 or 4 consecutive defeats at the hand of the tutorial boss! I just say no to the duel, get my shield up and back pedal while ordering a charge from my troops. I think it would be best for this end phase of the mission to have some lighted torches to illuminate the scene; they come at you quick from a short range and obviously the boss is generally better equipped and higher level than the player, so to be able to see perfectly would be helpful I think.
Maybe as the person mentioned above, the use of our tactics or roguery skills? Setting a fire or some sort of a distraction outside the hideout? Laying siege? Allow our entire army to attack?
I think having some sort of distraction related to skills would be good, yes, and maybe laying siege too- the bandits might barricade themselves in, which you would then have to batter down, and there could be a secret exit that you have to rush to seal off once inside (perhaps it's existence would only be discovered during the assault and felled a few bandits, and one of your men would shout out 'this bandit says there is a secret exit, they're escaping!', then you'd chase retreating enemies and follow them out of the caves/narrow mountain pass).
I don't think attacking with the whole army would be appropriate though; the point of the missions is that they are something different and not about using overwhelming force to succeed, and the logic is that the approach of a large force would prompt the bandits to flee and set up a new base elsewhere.