Fair enough. TSR settled out of court.
But the court case by Arneson is strong.
I think that one of the better analyses of the strengths and weaknesses of Arneson's court claims can be found in Game Wizards, which, as far as I know, is the only publication to correctly invoke Nimmer.
Based upon that, the litigation documents, and my own experience, my own opinion is that as a matter of law, Arneson's actual legal case was not very strong, but the combination of excellent lawyering, an unclear contract, and some incorrect attributions that made it into evidence were more than sufficient to get past summary judgment. And once you do that, you get leverage.
Again, this has nothing to do with "Who invented the game," or "Who deserves credit," or "Who is more macho," but just the actual legal claims presented.