There was a post made by a former reg here years back who put it better than I can, so I'll just sum up what he said to the best of my memory.
Mma and fighting in general are more qualitative than quantitative by nature.
Some stats are useful for sure, but unlike other sports, say baseball, the analytics shit doesn't play nearly as much of a factor. The sample size isn't there like it is with other sports to really use stats as your main go to for analyzing a match up and there is nowhere close to the amount of stats to look at, the advancement of numbers nerds and sabrmetrics, it's a whole different game of capping.
The eye test does your capping better for a sport like this. With other sports you might be able to win just based on going by the numbers, I know baseball and basketball bettors who make a lot of money based mostly on reading into the analytics rather than actually watching tape to make their decisions on which side to take, if any.
With fighting, you need to know your fighters and their styles more than just with going by numbers alone. I make no claim to be the most successful or talented gambler in the world, but I've been doing this a pretty longtime now and some of the best calls I've made have come from watching tape and figuring out the mentality, tendencies, and skill sets against different types and levels of fighters and how they stack up.
So yes, by all means use stats, but I would suggest you watch tape first and foremost, cap your fights that way, then go from there.