By themselves, Kushina, Kakashi Summer then Naruto SOSP. Now if they have specific teams or in certain events like arena, Kakashi summer might be better than Kushina. The bad part is that Kushina could probably one hit Kakashi on an even round, but in the end it really comes down to init. In most cases whoever is faster will win unless you have some other overly-powered ninja on your team.

As pos 1 minato is better, Nagato is better as a support. He c*ed as a pos 1, however since he has no scaling at all, he won't be very strong.