Current expansion limit on teams is 30 players. A number of players / teams have worked around this by establishing "academy" teams. This has worked for many teams as it provides a place where lower level players grow their characters into strong ones able to support the main teams status in the ranks.
Could this development be made part of the game somehow? As it is, only player agreements and the need to transfer players between teams to provide resources to the academy.
If a some sort of link was made available to the main team's leader and advisors once the main team reached a set development point (75 to 100). Such a link should allow them the option to donate to the academy as well as invite new players to that team.