If you're already experienced with Battle Brothers and have sunk many hours into the game, the guide may not help you much (or even at all). I run this setup when I'm looking to test stuff without worrying about losing the game. Your own skill comes into effect, of course, but the builds outlined here will definitely help since they're designed to minimize player error and maximize efficiency (both through individual perk choices and team-wide synergy). It aims to help you build an all-star crew of veterans that can handle any encounter while suffering a minimum of casualties.
This is a guide on how to reliably beat the game, regardless of difficulty.