To do a 30-team league, there would need to be expanded roster sizes and/or less restriction on playing time. Or perhaps an abundance of replacement-level players available. Since the league would be using so much more of the available At-bats and IP, it would be really tough to make up for any injuries. This could be rectified by having players have default stats if they have less than a certain amount of ABs. For example, I could bring up Rickie Weeks or Brandon Phillips, even though they have no major league ABs, and they would hit 200/260/320 and play below-average defense. Otherwise, it would be too frustrating.