I think a big part of this would be to take a page from WMMA and actually have to book a location before the day of the event. It forces you to think proactively, and can reward ambition or punish you for the same thing.
In real life you don't just say "We're gonna run the 50,000 seat venue"
You have to announce it months out so that tickets can be sold, you have to make sure your promotion is booking those big matches to get them in the building (which is already in game but could/should be expanded upon). If AEW announces a gigantic show anticipating tens of thousands of fans, but then WWE swoops in and signs their biggest draws, it should hurt. It would likely be a financial disaster with no ticket sellers or money matches for a giant building.
Currently you maybe see a couple thousand difference based on who is on the show or not, even with a max figuehead. I feel like it's weighted far too much on the promotion and not the star power of the roster. A visible example in the real world is NXT who could sell out the same NBA arenas the main roster was doing, but the same show with a focus on rookies, on the same network, and they don't even approach the 5 figure attendance marks.