This is a very interesting question that I had been asking myself, @Amanda Davis.
I just tried this and it seems to work.
In TBM Studio go to Project / Report Collections:

You can move around the reports by clicking the three vertical lines to the left of the name and dragging and dropping the ones you want to move to the desired position, the first one being the one on top:

The next time you access the collection it will go to the first one on the list.