First of all how much ram speed you need considering that most systems at high speed not stable. And intel doesnt benefit as much as AMD when it comes to memory speed. Correct me if I am wrong. Second, you are telling me you would pay 299$ for z790 Tomahawk rather than MEG Z690 Ace for 249$ for instance.

Z690 or Z790. Both works. So if you find a better z690 for the price get that one I suggest.