Honestly, I think it would be kind of natural. I mean, if I met a different version of myself with only a couple differences, I'd probably find them an insufferable shmuck. More on point, if you showed each version of Superman the other takes, they'd probably find the tellings oversimplified or overcomplicated, insincere or overly maudlin. And multiply all that many times over actually meeting those guys. I don't think they'd be mean to each other--the costume joke hardly counts--but there'd be plenty of comparing notes.