Ocean, Mages, and Taliyah all need to be changed
Ocean alone has the most internal synergy of any of the other units. Their ability to passive gain mana wouldn't be as bad if items weren't a factor but they are, units like Nami or Taliyah combined with ocean allows them to just perma spam out abilities and lock half or sometimes all units out of the game, which is the exact reason why Glacial is so stupid and hated.
Since we don't have any items that completely prevents cc for the entire round other than the insanely busted Olaf's ability unless we have RNG to give us items to instamurder their team not much can be done about this. Especially if you toss an basically any summoner into the mix so the targeting gets locked off the actual units for the entire fight