I don't see any correllation to stadium size to success. Examples include
UAB.....big stadium, worst case scenario
FIU......tiny stadium with new smallish stadium & after 3 years they still suck
GSU Atlanta.....huge stadium, terrible teams
GSU Stateboro.....Stadium about same size as Tulane's new small stadium, results very good so far
App State.....see GSU Stateboro
North Texas......Nice new stadium, new conference have done nothing to change there results established the previous 5 years.
Tulane.....Big stadium, results were terrible. New small stadium, looks like they have improved some, not much but a smudge better than before.
USM......One of the largest on campus G5 stadiums. Last 3 years have been worst case terrible. Can't even beat the bad teams in a conference with a large number of bad teams.
SMU......New very nice stadium after playing in Cotton Bowl for years. Results the last 5-6 years? SMU has been consistently one of the worst teams in 1A.
UL.....New expansion last year with Sr biased experienced team. Against OOC.....results were terrible. UL was probably one of the worst of any Sunbelt football program last year in creating a negative perception for the conference. Our OOC performance flat out sucked.
UTSA....new team, huge stadium after 3 years results have been pretty bad. Had a Sr heavy team last year with all expecting very competitive results and didn't come close to expectations, bottom feeder in a conference that had 8-9 very bad teams.
CC.......based on the above, there chances to be competitive? About as good as any team in any G5 conference.