Oh damn, yeah I used to make decent money, couple thousand a year doing this for league of legends when I was an avid follower of the professional scene in college. The key was to watch for the up and coming Chinese and Asian-Pacific teams who always had the best top lane and jungle play during that era, really easy to boost your team stat lines, with whole strategies around feeding those lanes. It was pretty easy because most people just obsessed over Korea, Europe, and NA, which was understandable for Korea, but NA never really had the best players for anything (maybe Sneaky?).

As well, all of those teams focused on methodical mid and bot lane play, with some exception (Unicorns come to mind). As well, grabbing Korean players was honestly sub optimal in a fantasy meta, because Korean teams were so cautious due to how easy it was for their meta teams to snowball and win mid-game, but that made for low kill average games. Easy money all things considered.

These days idk, I don't have the time to watch everything you need to watch and I'm sure the meta is different now.