Isn't everyone in the Mojoverse the only version of that person in the multiverse? I know Mojo's unique in the multiverse. I thought that might apply to everyone there. I can't recall seeing Longshot in any alternate realities, but to be fair, I never paid much attention to Longshot anyway.
Anyway, Vanguard's right, it's the Longshot we all know and love, but he was captured at some point by Mojo and had his memories wiped.