Of course I've cheated at CM/FM, everyone has.
I'm currently at pre-season in 2031/32 of a network game of FM13 with some friends. We started it in lockdown and that was the most recent version we all already owned. We play most weeks and it's immense fun, with no cheating (other than exploiting youth intake days).
I got sacked from Cardiff within months of the game starting and then got the Watford job, with them bottom of the Championship ship. We've now won 8 PLs, 4CLs and about 30 other trophies in what has been described by some as "The Hornet Bastard Dynasty". It's very competitive but our four teams of Watford, Derby and West Ham have risen to the top alongside Arsenal to be the best teams in the world.