Every artist who had a song that they were featured on (particularly Mr. MFNE). I like most of the tracks on Heems' last mixtape but only when Heems wasn't rapping. The guy has got some pretty neat verses but is really inconsistent.
Lol they were more famous than any other artist on that song
That's debatable and completely irrelevant. That song is near flawless until Heems gets up on it. It's good because of everyone else on it. They somehow have found a following outside of that but to say they're bigger than Danny or even El-P is a little speculative
Fools is livin' in the wrong household though. I don't think we can honestly speculate who's more popular but I know that I, like many, was introduced to them through features on other artist's tracks. I know very few people that honestly enjoy their music outside of features and I doubt they could be big on their own.
I was going off my experience as everyone I've met with an opinion on the topic tends to agree with me. Mind you, thats a pretty limited frame of reference. As far as I've been following them I've seen them as nothing better as shitty rappers ruining otherwise fine songs and always assumed that that's how they got big.