We can maybe both crown a "7x6 c4 champion" and a champion with all the board sizes.
Yes but what if there's no champion after many, many games in 7x6? I suspect that's what would happen if there were a real-life world tourney, there would be like a 5-person stalemate. If the tournament were today, that wouldn't happen, but if we heard an announcement that it will take place in a few months, we'd all start training really hard and several of us would be flawless by the time the tournament started.
Actually many of the tactics might also be diffrent because there exists many winning themes in the other board sizes which can never arise in the 7x6 board size
The starts/antis are different because an extra row or column can greatly change the effect of certain moves, but I still say the tactics are the same. Setting up threats involves the same exact thinking: combining diagonal and horizontal attacks to make a threat, using one type of threat to make another (e.g. even to make an odd), protecting your threat from being negated, using zugzwang to make your threat, etc. etc. Maybe on a bigger board, more things are happening at once than in 7x6, but it's more of the same things.
I also doubt that all the good players knows how to figure out the rowsystem for other board sizes because many of the good players havnt even played any other board size than 7x6.
Well they should know :O
Even if you don't know how to figure it out, you can just memorize 3 rules and know the strategy for any board size automatically:
Even area, Even height = 7x6 strategy
Even area, Odd height = 8x7 strategy
Odd area = 7x7 strategy
From those 3 rules, if you tell me the board size is 5338x6043, I can tell you it's the same strategy as 8x7, because the area is even and the height is odd.
So in general the first 5 moves of the game is just going to be played by intuition
This I have to agree is true if the board size is new to you. Unless you had like 10 minutes to think about each of the first few moves. Maybe that could be a rule in the tourney lol. But maybe it's not bad to test a player's intuition, just hopefully both players are unfamiliar with the board size so it's a test of both players' intuitions.
Maybe after the 7x6 segment of the tourney, the "random board size" part, instead of playing 1 random board size until someone wins, it should be best of 3 or 5 sizes (and then another best of 3 if no one wins), so that the player with better analysis and intuition wins, and the luck factor is reduced (so if one player knows one of the sizes by memory, and opponent knows another size, the two will cancel out and hopefully the 3rd size will be one that neither (or both) player knows).
Heh i wonder why i'm discussing this at so much length, it's not like there's ever gonna be a real c4 tournament =(