In 2013 it looks like we'd got to where we were at the end of flash. Use non ranked rounds (best of 3's 5's etc, maxing par 3's is still fairly common I think) alt shot etc to level up and get the good equipment then win MP games, premium tournaments, brackets or whatever.
The fact that the people that started these accounts knew to do this usually meant it wasn't their first one (account). So you have people that were a high tier with good equipment playing at lower tiers. This got even worse with the new XP system when massive XP bonuses could be picked up simply for consecutive days played, there were also some glitches that helped those people along the way.
I think level adds to the tiering up, in lower tiers, in the new game but I'm not sure how exactly.
WGT does ban multi's when they find them but these are almost always the harmless ones, they get to legend and can't shoot a decent score from these tees so start again. These players don't play for credits but do something daft, post in the forum from the wrong account or something like that. There are those here that will then report them.
The one's that win credits would take some effort to find, not an awful lot but some, so are left to fleece other players.