Great analysis! I do have to question how you dealt with Burnie and Ashley though. You seem willing to give Burnie full credit for Rooster Teeth since he was a co-founder, but you only took into account the company's main YouTube channel.
I suppose only the main channel makes sense if you're only looking at Burnie, since that's the channel he appears the most frequently on. But Ashley is a co-host of The Know and The Patch which are only on The Know's YouTube channel (781,664 subscribers), so it seems weird to exclude her/that channel's numbers. And Burnie also is part of the "Podcast Crew" on the company's Let's Play channel (3,519,694 subscribers)--he's not a huge part of the channel but a common enough occurrence that it might be worth noting.
Also, if you're more willing to just flat-out give Burnie full credit for all of Rooster Teeth, there's quite a few other channels that are under the company:
The Slow Mo Guys (7,412,601 subscribers)
Achievement Hunter (900,113 subscribers)
Funhaus (868,546 subscribers)
GameFails (549,984 subscribers)
Red vs. Blue (379,373 subscribers)
AH Community (364,921 subscribers)
Game Kids (85,032 subscribers)
Technically ScrewAttack is also part of RT, but since they merged just recently and developed their own brand and following independently, it seems odd to include them.
It's all sort of a mess though. There's probably a good chunk of Slow Mo Guys subscribers who don't know what Rooster Teeth is, let alone who Burnie is. But the main host of the channel, Gavin, is Creative Director at Rooster Teeth and the channel only really sort of exists because he was trying to get a work visa to join RT. So it would be weird to count SMG subscribers, but it would also be sort of weird not to.
And then you have to remember that RT has its own site and video player, which is where a lot of their views for Red vs. Blue and RWBY go because they release there anywhere from a week to a year earlier than on YouTube. And you have to realize that there's probably a lot of crossover between subscriber base for most of their channels.
I guess what I'm trying to say is that determining "fame" or success on the internet is weird. Burnie and Ashley have a lot of weird facets to consider, which makes me think everyone else on this cast does as well.
Still, really interesting, great work. Some of these people have bigger/smaller followings than I thought!