Ok, let's make it $15M
22 x $560k players + say 3 x $360k players for loop and cover, and 5 x $160k players. Leaves you money for 3 trades.
How will you go, when you get more than 3 Suspensions/LTIs in the first 4 or 5 Rounds, with no trades left, no mature Rookies, and your $550k injured Prem can only be traded to a $300k MP, because you have no trades left?
I would suggest you still need a balanced approach, and need to grow to a full Prem team. Getting a full Prem team earlier would keep people more engaged longer. Knowing you never have to run out of trades has the same affect.