I would recommend only picking one retro.
Just because one is popular and obvious doesn't mean there are going to be two retros. Really I think that is detrimental. Retros are good for the nostalgia or value, but overdoing it is well...overdoing it. It should be a one per game tradition in my opinion.
Of course that may also be because I see some rosters with several characters that are unlikely rather than likely, or just too many retros. Basically, when I see a roster with (for example) Anna, Daitoryo, Lip, Muddy Mole, Takamaru, etc...
Like one or two are fine. But don't go adding like 16 characters like that. That isn't going to happen. That's not a prediction, it's a bad guess.
Mini rant over.
I'm surprised we haven't gotten a stage reveal in awhile. At least we get Diddy this week.