It’s rare in single-player games that you can bounce back from a setback. Usually you are either progressing towards victory, or you are defeated.
Take for example a typical game of Civilization. At the start (on a decent difficulty level) you are behind the computer, and you either slowly climb up, or you don’t climb fast enough and lose when the AI beats you to an ending or defeats you in war via superior tech/units. Its very rare that you can fight the AI, lose a bit, and then come back. It’s also pretty rare that you can be winning and have the AI bounce back against you.
The same can generally be said about XCOM. If you are keeping pace, you are winning. If you fall behind the pace, you will lose and have to restart. If a mission goes very poorly, you again lose (this is less the case in the Long War mod). The balance just isn’t there to get a very tough mission, have it go poorly (multiple soldiers die), and for you to bounce back and recover.
Battle Brothers manages to achieve that feeling of things going south, but still giving you a chance (though no guarantee) that you can still turn things around, and its a rather thrilling feeling. I’ve mentioned before that interesting decisions pop up when a guy goes down, or gets serious injuries, but as I finished my first epic event, I can also say that those type of decisions also exist at a higher level as well.
Here is how it can play out. It’s around day 90, and you are doing well. You have a full company of 12 brothers, all decently geared, and your supplies/gold are solid. The epic event starts, and you take a 2 skull contract. That contract ends up being far more difficult than you predicted, but you only realize this after the fact. Now you are faced with a choice; fight the battle and potentially lose it all, or decline the contract/fight and take the reputation hit, along with the epic event getting worse (a town is burned, for example).
Assuming the decision you made didn’t result in complete defeat, you must now recover. The tricky thing is what do you do? If most contracts are event-related, maybe more of them will be too difficult or risky, but you have to do something or you will run out of gold/supplies. Wandering the world looking for fights is an option, and a viable one at that. Taking one-skull contracts is another option, though that might be tricky as the pay may not justify your ongoing expenses, or the gains might be too small for the amount of time spent.
The whole time, you are balancing getting stronger with the world overall getting more dangerous. The more you push yourself, the faster you will progress, but pushing too far could either result in a total defeat, or a setback that requires more recovery/pushing. The epic events just ramp this aspect up, with more dangerous fights and contracts coming up, along with far greater rewards. It’s an impressive display of game design and balance, and makes the later stages of Battle Brothers as engaging and challenging as the early.