Lots of clubs here field "A" teams and "B" teams, especially at levels lower than 4.5 where there are more players.
The A-Team has assorted ringers, scoundrels, and seasoned veterans who seek to win the league while the B-Team usually has everyone else of the rating, and some younger guys who want to play up as well.
The in between dilemma really gets younger guys who have doubles games which are much weaker than their singles games.
Since the strongest players on the team usually play singles a guy can be a good amount stronger than all the singles players at his level but a good amount weaker than the singles players at the next level. But due to his proportionally weak doubles game he can't play doubles at the higher level and finds himself out of a job.