No, it will be pretty much impossible to cheat, because the rest of the league has to agree that it is a fair trade. So if you are trying to make a friend's team really good, it would be obvious, and people would just say no to the deal.
Would it not be more realistic to let new owners just inherit the abandoned teams if a new owner joins in the middle of a season? It starts out by saying that new players are newly hired GMs, so why not just let them take that situation. It will decrease the number of retired players as time progresses.