I'm sorry, I really don't see the hype of this game. Nostalgia maybe? I mean, it's fun if you want to mow down zombies, but there's absolutely no strategy involved.
You want to know how to win? Easy.
Step one: Fall back.
Step two: Open fire as early as possible
If you REALLY want to be finnicky with it, get out of the forests and into open ground.
That's it. That's all you have to do to win 9/10 engagements in every level I've played thus far, and for the odd chance the zombies close in and win, it's fine, you got multiple other forces to fuck them up.
So, I guess, as a game, it's great; as a strategy game, it's not one.