[Racer26]

That should pretty much put an end to this speculation nonsense. CollegeFIRST, with AERIAL vehicles, and so on, needs 3 FRC fields. By my count, that means they're fitting:

3 FRC Fields (Divisional Dome 1, Divisional Dome 2, Einstein)
3 CollegeFIRST Fields (All Your Base, FIRST Flight, The Best Trajectory)
1 FRC Field sized area for FTC
AND FLL (atop Einstein)

inside the Dome.

Plus: College level-FIRST, including flight? Yeah, I think that trumps 2 FRC fields needing to be in the dome.

EDIT: All that being said, I still think they could have fit it all in. Arrange the 3 CollegeFIRST fields close together in one end-zone, Einstein, stage, and FTC in the other endzone, and 4 FRC fields in between. From what I saw in ATL last year, there was a lot of under-utilized space on the floor of the dome, and my understanding is that STL is actually BIGGER than the Georgia Dome.