Honestly the answer is right in front of all of us. It's not really worth your time or effort to please the already big accounts, unless you can somehow create something that they might retweet and pull in some followers for you, but that's reliant on piggybacking someone else's success.
The answer is, well, ground zero. If 10 comic artists have no followers on Twitter, if they follow each other and interact with each other, they grow bigger. Social media is pretty reliant on you having a base community--You can't really start a social media account then expect a community to roll in. At least, not in today's algorithm.
Numbers mean so little to be honest. Numbers really have no worth, but, it's nice to see that people are reading your pages. It really is just about the quality of the characters who follow you, not the quantity.