The army skin has properties hat reduces bullet damage by an amount as comparable by the hero skin increases speed. I don't know if that was the "hack" he was talking about.
The arma engine isn't the only one to implement realistic ballistics, As far as I know, the STALKER engine is great, perhaps even more realistic, especially with the complete mod.
I can see someone ghosting to the lighthouse or at the water around the back. Having someone as a lookout at the lighthouse is a good idea but they'd be the first dead against a sniper.
Also as you know the hero skin increases running speed and the bandit skin negates broken bones, the soldier skin slightly reduces bullet damage so keep it.