I suppose you could learn something about tactics from video games. You can also learn about war tactics from Chess, or Poker, or a thousand other things. Games in general help you in the practice of thinking. Ill bet that in a simulated firefight, a gamer would do better then a non-gamer. But that's not because of any actual training, but because a gamer has learned to plan a strategy.
Though I suppose, if you wanna get really technical, a video game might instill the absolute basics to a limited extent: Stay behind cover, check your corners, that sort of thing. But in most situations, if your trying to apply video games directly to reality, you are more apt to do something stupid.
Ill say that it might help, but don't count on it. Like, at all.