The combat portion of the game is strong. There is a good variety of weapons, backgrounds and enemies. However, outside of combat the gameplay is much weaker.
Games of this genre tend to add minigames to keep the gameplay from going stale. Sid Meyers Pirates had dancing, land combat, and treasure hunts to keep the ship combat from becoming repetitive. Mount and Blade had assassination quests and castle building. Battle Brothers needs more content outside of combat.
Some ideas would be, building a company HQ, assassination quests, ability to wander through towns, fighting rival merc companies (swiss vs landsknechts), crime and punishment for serving robber barons, committing banditry or enforcing laws for a noble or town, reputation ( is it a ruthless merc company that takes no prisoners, and fights to the death like the Swiss, or something more civilized ), more trade options, an option to train your troops while in camp through a 1 on 1 combat minigame, etc.
Also the game is missing horses. Will that be added to the game at some time?