Flagrant fouls, or even bigger violations, don't normally carryover when changing leagues.  The player starts over with a clean slate.  If say Lebron James had punched a referee  in the face during the NBA finals then decided to play in Turkey, he wouldn't be suspended for that in Turkey.  Same with drug & other offenses normally.
If this flagrant foul thing were to be implemented, how about penalties to non-aggressive players?  Maybe non aggressive players like to sleep in & show up late?  Be late for 3 games/practices, & be suspended a game.  
An intimidation penalty.  Like: "Player X is afraid of Mr. Thug & refuses step foot in the paint, drive to the basket, or go after any loose ball in his vicinity".  A player's intimidation factor goes up with each flagrant foul.  And quintuples with each suspension!  Eventually non-aggressive Player X refuses to even take the court against Mr. Thug!
New Trainer specialty:  Phone user.  He calls your non-aggressive player with his cell-phone in an attempt to wake him up so he won't be late.  Since cell phone coverage is spotty it doesn't always work.
New PR specialty:  Paralegal. He uses legal jargon in an attempt to get the league to reduce suspensions to aggressive players. He's not an actual lawyer though & isn't always taken seriously.