If we took the point each team was at in PQ2 and put them in a fight, which team would come out victorious and why?
My bet is on the Phantom Thieves. Akechi alone is a tough fight, but with Joker and the others, this team is unstoppable. The Phantom Thieves will also be the quickest team from stealthy silently sneaking around in the palaces, so evading enemy attacks should be easier for them. Also, I'm pretty sure Futaba could hack into Aigis, which would put Sees at a major disadvantage.
The Investigation Team doesn't have much to combat the other teams, so I don't think they'll perform well in this battle. Their best bet is having Rise analyze for any weaknesses in the opposing teams, and having Naoto formulate an effective battle plan. But Sees has both Fuuka and Mitsuru, and the Phantom Thieves have Futaba, Akechi, and Makoto; which are just about as good. So, the Investigation Team could definitely put up a fight, but they aren't coming out on top.
And finally Sees. Akihiko and Aigis are the heaviest of hitters on Sees. One's the textbook definition of a badass and the other is a toaster with a machine gun. However, if Futaba's hack was pulled off then Sees is mega screwed. Otherwise, I think Sees might stand a chance and could win if the Phantom Thieves were caught off guard.