>>32100853A lot of the time it can be a crapshoot and whoever gets better spins is the winner.
One of the Sylveon on my team is dual c-leveled and has a good chance vs most rounders (all my other rares were shitty so I decided to c-level it for the tournament.
A big key to beating other round teams is to get my C-Leveled Sylveon up against another Sylveon, and make sure that I don't have Wigglytuff matched against their Sylveon because Wigglytuff has a weaker round and smaller round slice.
Flygon is there to be anti-rush/anti-offense and overall Vibrava might be better vs other round squads, but its purples can be pretty useful against round teams depending on the situation; it's helped me win a game by picking off a Wigglytuff goalie with Draco Meteor before
So overall I just set-up my defense, get everyone positioned and begin by attacking with the c-leveled Sylveon. Once you kill one rounder, everything becomes a lot easier and you have more license to be aggressive.