What you need to do is grab all those sources, and only use what they say to create the article. You can't use anything you yourself know, or what the FH site says. If you use what you know, you'll need to add [cite needed] after each sentence. If you use what the FH2 site says, you'll be advertising. Or something like that.
When creating lists of maps or equipment, you can use the FH2 site I guess.
(btw, anyone notice the idiots at EA claim FH2 is a mod depicting the "Great War"?)