To me there is a purpose in starting ML with a good team. Experience. Start off by beating opps on Top Player with a good team and then progressively lower your power. Now actually, after playing 3 matches into the new season with Valencia I came back to the default players game. Even D2 is challenging, as I made it consist of Fiorentina, Aston Villa, Tottenham, Lazio, Villareal, Sevilla etc. I'm 3 matches away from the end of first season, 7th place in the league and running a 2-loss streak - to FC Groningen and Aston Villa. Games with Zenit, Fiorentina and Villareal left.
During the mid-season transfer window I released a few of the oldest/weakest players from the team, bought like 5 or 6 youngsters (trying out Kim U Don for the first time, he gains 20~ exp points to his skills even at a loss - immense!; also got Wiart, Griffits (this guy has 65 stamina, ouch), Shubin, Sasaki and Lorenz... that makes six.) and loaned Borriello for 2k~, because I felt it's not an abuse. Just playing some reserve striker who accidentally became the strongest point of my team. I still have to get 1000 points to pay for all my players...
Well I mean the bottom line is always fun factor. If you have fun then that's all that matters... but I feel you gain much more experience with the default guys, cause .. if you can compete with that group then you can certainly whoop some arse with a more powerful squad