Inter-clan (ONLINE) tournament for Heroes 3.

but for example, I don't know how to play at 160% at all... because I only know the tactics for early development at 200%, and at 160% - I'm completely clueless.

I, for example, last played at 200% a couple of years ago, so I didn't immediately remember the development strategy, but I still managed to play somewhat in the seasonal tournament without preparation. Not as well as I would have liked, but nevertheless. ;)
A true Heroes player should be able to adapt to anything :D