The quickest and easiest way to get this achievement is editing players, simming, and abusing saves.
Before the match go into settings and edit a few players of a good team. I used Arsenal and edited Walcott, Ozil, and Sanchez. You don't have to edit all stats, just attacking ones, speed etc. This will make your players 107 rated.
I also signed a few players, so I had Pogba and Ibrahimovic in the team too. Didn't bother with the defence.
Now you can sim all matches and you will find you win
nearly every match. You will win the league easily but save before cup matches, as you may lose the odd one. Obviously have auto save turned off in the settings, and reload if you do lose. At the end of the season you should have won everything. Took me 50 minutes simming and 10 mins set up.
Check out my solution for
for for a bit more info on how to get all of the master league achievements efficiently.