I think just working from a single cartoon (which seems to be all they have the rights to) rather than drawing characters from four toylines, four cartoons, minicomics and concept drawings will work in their favour. There are certainly a lot less Thundercats characters that need to be done in order for the line to feel reasonably ‘complete.’
I think most of us feel that the MUST-do characters, the bare minimum to produce without seeming like a failure, are Lion-O, Cheetara, Tygra, Panthro, WilyKat, WilyKit, Snarf, Jaga, Mumm-Ra, S-S-Slithe, Monkian, Jackalman, and Vultureman. (13 characters).
To have greater ambition, though, they probably also need to aim for the three ‘new’ Thundercats, the six Lunataks, and important supporting characters (mostly any recurring ones, but there are a few iconic one-offs) - Hachiman, Snowman, Willa, Mandora, Hammerhand, Driller, Ratar-O… you get the idea.
If they do all of those and there’s still a hunger for more, then they should definitely continue with the more obscure characters, but I think starting reasonably modestly is a good idea.
Being harsh in my thinking about who needs to fit into the second group, I think I can get my wishlist down to about 40 characters, which is less than three full years’ subscriptions-worth. I think barring misfortune, that’s pretty doable, and certainly looks possible compared to the MOTUC 200 or so.