I edited my previous post, to add "below Legend Tier" because as far as I know, sandbagging and multi-accounting don't have much effect on Legend and Tour Legend payouts (if those forms of cheating even take place at those Tiers at all), since those players are presumably at the top of the skill pyramid in this game anyway.
Jimbog1964: Would it make a difference to competition?
I think if the main incentive to cheat (easy credits) is eliminated, most of the cheating will stop. The only remaining incentive would be "bragging rights", so cheating would not completely disappear. But if all the cheaters win are false bragging rights, so what?