Auto-translated
Nothing prevents holding a tournament with two winners. One for SoD, one for HotA.
Right now, I see the parallel structure as a tournament with three winners.
Two parallel brackets – one for SoD and one for HotA – are two separate tournaments.
They have two separate winners.
From those who played in both brackets, the top 4 (top 2 from each bracket) compete at the end for the absolute winner in a mix, playing both SoD and HotA.
There may be nuances – it's not a problem to figure them out.
And there will be no need for any arguments, no need for anyone to prove anything about what is better or worse. Everyone plays what they want.
Those who like both and have plenty of time can play both.
And you can easily post on the HotA website the winner of the HotA bracket (specifically the HotA bracket, not the final mix).