IMHO they SHOULD have a Marshal on each of the top two cards, or at least one dedicated to the top two cards (which should be next to each other in order). People can complain about the fairness, but the most money and prestige are on those top cards, especially in later rounds. I'm surprised the top cards don't have dedicated marshals.
This also shows how the sport has grown. Yes, back in the day, players policing themselves and each other was fine. We also policed ourselves playing casual touch football as kids, but the NFL isn't going to self-police anytime soon. So maybe Disc Golf needs to think about this aspect of their growing pains, as well.
Comparing the NFL with disc golf is kind of absurd. Comparing disc golf with nearly any sport is overestimating the popularity and stature of our game. I don't think it is any more difficult to self police in our game now, than at anytime. Video and social media just makes it infinitely easier to discover errors and endlessly debate them.
Dedicating marshals to top cards or even more is a fine idea, but I am not sure TD's could put together the volunteers to fill those positions.