Player rating for tournaments across all installments of Heroes.

Yes, I think that with the right organization of the tournament, and with 5 people per team in the fourth stage, it is quite feasible. For example, in the first stage, around 20 participants have already registered. Even if only half of them send in their saves, that's twice the minimum number of participants. So, I think there will always be a quorum in the King's Bounty tournament. Although, if it doesn't reach that number, I think it should still be recognized as a ranked tournament, just like an official one.