Might acutally give it to Passione given their haxes since GreenDay and Secco alone can make a large portion of ninja start to fall. Pesci and Risotto can stealth kill and Notorious Big is literally unstopaable with other stands guiding it as well.
Class A overwhelms the group. Formaggio and Melone take way too long to set up properly and would fet overwhelmed. Illuso could just as easily grab a memeber of Ua that can easily one shot him. Pesci falls quick to mostly because he would be out in the open and vulnerable to all of Class 1-A's quirks.
Risotto, ghaccio, and prosciutto are proabably the best bets but even then they have problems. Proscitto's thankful dead could potentially kill Bakugou and Todoroki but nothing stops that from being in reverse for Todoroki's ice. Plus he would have to be extremely close if he wanted to take them out. Risotto is the powerful person hear but there are still issues. Nothing stops class 1-A from nukeing the enviorment tell they get to him and we don't really know how well risotto does against mutilple opponents. Either way the whole turning blood into metal trick takes at least a couple of vauable seconds that could mean the end if others get to him since the stand as a short range. Ghaccio is the best in overall direct combat but get's completely ragdolled by anyone that out ranges him or overpowers him since his stand's ice ability would require the opponent to be directly touching him or to be on the ground. Eventually they would get lucky and hit his neck.
Overall La Squadra is formidable but their an assassin team and don't do well fighting against full groups in open combat.
I think either Connor or Edward. Ezio is fast and durable but for me personally he isn't the greatest of fighters but the best assassin. Connor and Edward both are assassins but have unique fighting styles that can upset more expirenced assassins. They also are the most direct and combat able out of the 5 right now with enough expirence to match.