I've been told that krav maga is the art of cheating but I've also heard about the insane amount of gouging involved in RAT but its origins seem pretty mysterious, what so we actually know about it?
I am not sure what you mean by "rough and tumble" martial art style, but wrestling is one of the oldest forms of martial arts and has a very well documented history and several surviving traditions. Historically,it was much more similar to krav maga and MMA and was downright brutal, with eye-gouging, joint breaks, and all kinds of dirty tricks. The earliest extant written source on wrestling that I am familiar with is the Oxyrhynchus Papyrus. It dates to the 2-nd century BC and is rather fragmentary, but shows that even then they had a system. There are a number of images, frescoes, statues and literary references that go further back than that. We also have a number of complete manuals surviving from the medieval period and later on, that provide a lot more details and allow us to reconstruct these arts in detail. And manuscripts aside, there is a well documented tradition of folk wrestling and martial arts, prize fights and tournaments and gladiatorial fights going well into the 20-th century. Some of these, such as oil wrestling survive until today and are quite popular events in say Turkey, Greece and Bulgaria.