actually, fasa wasn't the creator of battletech, while yes they did make a lot of the rules/mechs/guns/equipment.
ok, there was this company that made Battledroids, it had the unseen mechs in it, and they did get permission from harmony gold to use the art. well the company sold Battledroids to fasa, and fasa renamed it battletech, and they kept making the stuff till harmony gold realized that fasa was useing the art w/o their written permission (because fasa misplaced it somewhere, so they had none). so now Battletech is owned by Topps, with catalyst doing the major stuff for it now. so battletech is pretty much all over the place while robotech has stayed with the same owner.
now a little fun fact about smith and tinker, the founder had founded fasa before founding smith and tinker.