Removing the X3D from the pool is kind of a bad start, but if its advertising you seek, high numbers are appealing, so a Ryzen 9 would be my second bet. Something along the lines with the 9950X.
Why the 16 vs 12 core, well, while CoD doesn't really seem to care about 6+6 CCD with a difference in fps, like 6 more for the 8+8 9950X, in some other games like cyberpunk it will indeed matter and the difference may be up to 15fps. But both are good picks.
Don't push the ram too much, 64gb will be enough. 2x32 so you won't burden the IMC and get faster memory and lower latency that matters most. Check the QVL from the board and make sure to get EXPO certified memory to avoid future issues.
As for the card, nothing better than the 7900XTX. You'll be having around 130/140fps solid at native 4K max settings on COD MW3 from what I've seen online.
Then its up to your taste about fans or bling bling.
Good Luck
The Englishman