It's unlikely to be that many multis, probably they have just logged in using a network that is getting bounced around different ISPs, a popular VPN, or something else like Tor.
Possibly multis, but not enough evidence to say that for sure. If they are sharing a network, they aren't allowed to attack together anyway, and will receive warnings for that.
I don't believe you're multis. Verification is always an option if you want and want to play together unrestricted https://politicsandwar.com/account/verification/