They'd probably be better just scrapping the MRP and just going with set punishments.
Something like:
Red card = 3 match ban, no fine.
1st yellow of the season = fine.
2nd = 1 match ban
3rd = 2 match ban and so on.
Give the clubs the opportunity to appeal any red cards, and perhaps leave the door open to extend bans for more serious foul play,but take as much subjectivity out of the process as possible.