You would have another season to train your existing players so you would of had more quality compared to other teams in L10, also you wouldn't needed to buy many new players so you would of saved on tokens, you would had a better chance of winning L10 next season than L11 that you just been promoted to. If your not going to qualify for CL in the league season, then the best thing to do afterwards is don't come 5th,6th or 7th and stay in the same level and build up squad quality through training.
*Retired From Top Eleven*