Skill min/maxing works when players decide that it is easier to kill one another off instead of trying to complete the scenario. They then bulk up on combat skill combinations that allow them to cause the most carnage.
You'll find it in almost any game system that people have played for a while. They find certain combinations that work very well.
To get around this in the games I run, I set up the scenario so the winner is not the "last man standing". For example: you could set one scenario up on a snow-topped mountain. Gunfire risks bringing an avalanche down. Or set a turn limit that precludes players being able to just sit and shoot. One person told me about a player that would simply bypass the Encounter Markers and make for the obvious goal. I get around players like that by requiring them to have a key, map, sacred stone, etc. before they can enter the final area.
In the end, though, a wise gamer once told me that if you put two wargamers at a board and tell them their models have no weapons and are separated by an impassable river, they would still find a way to fight each other. So you just have to let players be players. If they have no interest in doing anything but fighting, let them. If they want challenging games but often find themselves just fighting because one player starts it, then design scenarios that penalize those who spend their time in combat.
As long as everyone has fun, that's all that matters.