I can see that for sales - doesn't really add up for loans, IMHO. I doubt if when a young player goes on loan to League 1 to get a taste of grown-up football there's much in it for the agent!I read an article about this once, featuring agents and others. The main reason seems to be “motivated seller”. Thinking of it like buying property, this is often a “chain”. So one player can’t be let go until another one comes in, for financial or squad balance reasons.
With loans, there are a lot of motivated buyers and sellers and it has just become an unwritten rule that business just gets done on the final day. Reasons for this are buyers being willing to pay what they weren’t before (desperation), clubs being willing to sell for lower demands, players worrying about being trapped at a club where they won’t play for another 5 months, agents lowering their fees to get moves over the line…