How is it more Logical that 5 is better than 6? We don't work for the company so we have absolutely no say in what is logical or not when it comes to their games.
Based on rumors I've heard though, its only Pikachu, Jigglypuff, and 1 5th Gen Pokemon. Victini, Reshiram, Zekrom, and Kyurem are supposed to be trophies/World obstacles like how Dialga and Palkia were in Brawl.
Zoroark and one of the Musketdeers were the rumored thirds from what I remember seeing. But I heard there were over 50 characters this time too, so they could be adding way more than that from each Nintendo Series games a lot of them from older games. (Someone said the guy from Balloon Fight was going to be in it)
They are also doing something brand new with the cross platform link up so we may get shafted on character selection since the Capcom inclusion idea keeps jumping from bad to good and back to bad in Sakurai's head. We've got a while to wait and we'll see some footage in June which excites me cause I wanna see what rumors are true. But as far as Pokemon is concerned, based on rumors we're getting between 3 and 8 as there was one about bringing back all the Pokemon so far plus some new ones.