Currently I have a php that has users sign up teams. Each team has multiple members. When we run tournaments such as 4v4's for example we wan't to make sure that every team signed up has at least 4 members otherwise they are to be deleted.
Currently we have to do this manually, and when there are many teams, this will become extremely tedious
Have you thought of issuing a query against the information_schema database and in particular the TABLES table. This contains all the tables in every database and also includes a field called TABLE_ROWS. For InnoDB this is an approximation rather than an exact number but for MyISAM this appears to be exact.
Hence, you could simply write the following (assuming you have admin access):
WHERE TABLE_SCHEMA = '<database name>'
AND TABLE_ROWS <= 4;