Fragger is without a doubt the strongest, well, fragger right now. But he is also the only assault class so far. Even Vassili is technically a recon and has interesting utility function with his heartbeat sensor.
That doesn’t mean Fragger should roflstomp everybody else in a duel, and if that’s really how it is in competitive then sure, he’ll have to be put it in line. It doesn’t seem all that bad to me, but the tournament should make things a lot clearer.
In general I don’t see a problem if teams fall back to Fragger whenever they don’t have a need for more specialised classes. We do have a problem if teams don’t pick medics because adding more Fraggers would be more valuable, or they never add fire support or engineers even if the situation calls for it, simply because Fragger gets the job done better anyway. But aside from that, even if teams put in two or three Fraggers at times, that still seems perfectly acceptable to me.
Comparing Vassili directly to Fragger isn’t possible IMO. Even putting the utility function aside, snipers always have a special role in games that requires unique consideration and balance. Nothing should be taken for granted, even the basic question of whether we want Vassili in the meta or not.