Suing will just lead to Disney coming around and fucking the rest of the star wars modding community once they've seen money is being made off it, and as a lead dev for a big MoW star wars mod the last thing I need is having the last 2 years of work be shut down by Disney. So while yes its shitty that there has been content stolen, the most they can do is have the mod taken down. So unless you want Disney lawyers starting to look at you, which if I recall correctly was the reason why IA was shut down in the first place (that being they didn't want to get hit with legal issues) I just made an account to respond to this, legally any and all content they've made star wars related belongs to Disney.
Because if there's any legal issue they can be legally sued even if they dont release his mod, in legal terms you have think, ever, ever in the worst case scenario.