What's interesting is the total number of bids from each of those conferences since 2014 (year that the BE and AAC reformed):

A10: 6, 3, 3, 3, 3 = 18 total bids
AAC: 4, 2, 4, 2, 3 = 15 total bids
Big East: 4, 6, 5, 7, 6 = 28 total bids

Even taking away the unique six-bid year for the A10 in 2014, the A10 and AAC have had a relatively equal amount of bids between the two conferences (which is undoubtedly why the AAC needed to add Wichita State in 2017). Davidson and VCU will routinely compete for at-large (if not automatic) bids for the A10 in a given year, and recent years have shown that Rhode Island, Dayton, St. Joseph and St. Bonaventure can grab an at-large as well too.