Wolfox

It is a bit obvious. The reason why I think Yusei stands little chance against yuya is the amount of boss monsters that yuya has. The four dimension dragons are already a thread to yusei's stardust. Then you have the odd-eyes combintions, the odd-eys upgrades saber and lancer (lancer gets pass all the traps), odd-eyes fusions and finally the palladins. So getting into any of these is quite easy for yuya. 

For yami this is more from a perspective that yami has access to some very broken cards that can easily win games on their own.

I'm looking at it from a perspective with the most fair decks. like n banned cards AT ALL. till yuuya will have an advantage against just Stardust, but stardust also has nice combinations like SHooting Star, majestic and quazar. against yami it will literally be who get's the ace out first and who does the best with it. granted I would love to see either in an anime style duel and be happy with any outcome. Yuuya VS Yusei could posibly even be a turbo duel depending on the setting