Jaiden also hires a bunch of other animators to pump stuff out as quick as possible and they probably don't storyboard stuff either, likely working direct from a script.
And if you look at Internet Archive and go back to two months after her channel started when she had five videos she had 12,220 subs and her highest-viewed video had 54,776 views, which Hannah has heavily surpassed. They're different kinds of animation channels for different audiences and so the comparison doesn't really make sense, mostly because Hannah's type of cartooning takes a lot more time and effort and thus she isn't able to gain an audience by sheer force of volume, but as far as the size of the splash made with her first proper video she's doing incredible.
I have sensed that the simple sort-of Newgroundsy charm to Satina is being widely liked on YT because many people are hungry for an older less cynical style of internet video-making that was done for fun rather than profit and that isn't part of the small group of common genres modern YouTube videos tend to fall into. Jablinski Games wouldn't be as successful if it wasn't Jack Black, certainly, but it also wouldn't be so widely loved if it wasn't so unpolished and unpretentious in a way that's a bit of a nostalgia shot compared to lots of channels that try as hard as possible to have TV production values.