I'm not sure if you're aware of how the ride works. There are four different rotating carousels holding multiple cockpits. After you see Hondo, you are sent to one of two Falcon "chess table" rooms. Each of these rooms has two of the four cockpit carousels attached to it via a hallway. After you are buckled into your cockpit, the doors close and your cockpit rotates to the next position, allowing for the next cockpit on the carousel to move from the unload spot to the load spot.
Not only would they have to have two Falcon mockups, you would not be able to see the whole thing, because they would have to disguise the fact that the cockpits are constantly being rotated out. So instead of having a full-size Falcon out front that we can see every single angle of and are free to take as many pictures as we want of, we would be limited to seeing a mockup of just the back of the ship. I'd rather just see the whole thing, it's a very impressive focal point in the land.