So we adding more Gms/supervisors. It would use up a lot of GM's time with the amount of trades that would go through as each one will have to be checked throughly. There is also a consistency factor as trades are always subjective. 1 GM thins a deal is lopsided while another might think it is fair.
I say there is no need for it, the transfer market works perfectly. There is no need to trade, you can sell your player and use that cash to buy the player you were going to trade for.