Here was my logic.
I assumed that the entire reason behind BUILDING a Multi-Williams CP was to PLAY the Multi-Williams games on it, thus my conclusion that you were planning to play Robotron with 4-ways.
If you're going to play Robotron, Bubbles, and Splat on your fighter panel anyway, why not just add ONE button to it, near enough to the left stick to hit with your thumb, and play ALL the Williams games on your fighter panel?
Then build an Assault CP (one stick of which needs to be a topfire, btw), toss in a couple buttons, and play all the 4-way games on that.
That makes a whole lot more sense, at least to me.
And I'm STILL trying to figure out why they didn't put Moon Patrol on in place of Bubbles or Splat.
No logic there at all.