Yeah, I was also thinking that multiple 4-ways might be overkill, but I wasn't sure what you might be wanting to do with it. I play Rampage with 8-ways and it seems 'right' so, if that's the main goal, I agree with the above comments
I have a cab with a CP that has two 8-ways, a trackball in the middle, a spinner offset above it, and a single williams 49-way to the left of the spinner. In a lot of ways, it sounds very similar to what you're thinking but I have a 49 rather than a 4 way. And the two 8ways are close enough that I can play Crazy Climber, but not so close that two players can't fit at the cp.
I built it a million years ago, but I'll see if I can find the layout so you can check it out