I don't think there's a single character on out squad of flying teen witches (With the notable exception of Mary Beth)  who wouldn't try to either kill or befriend another magical girl.competing for the same job as them, fighting the same battles as them and eating the same food as them.

And either way, that encounter is not going to end in a boring way. It's not going to be quiet, forgettable, or uninteresting. This would be good material for actually roleplaying, so trying to hide it or discourage it with a blanket statement like "oh, they probably already know each other" seems like a misguided move at best and actively malevolent at worst.