Yeah, it looks like the two campaigns could end up being only days apart, but that might not be a bad thing. Since the Z-Engine is being used for both games, there will probably be a good amount of attention on LabZero either way, and maybe that could open the door for some helpful cross promotion. Sites that mainly want to talk about Herds might still want to make a passing mention to Indivisible/Skullgirls, and vice versa, which would be cool.
You can also bet that IGG will go out of their way to highlight both projects, and the collective audiences for both could bring a lot of extra attention to the site. If both campaigns can be up around the same time, that might also prevent either one from stealing the momentum from the other. That was like the case with the Half-Genie Hero KS, where by the time it started, many potential Backers had already dumped their wallets on Mighty No. 9.
My money's mainly going to Indivisible, but I'll see what I got left to help out these guys too. Hopefully both projects can be successful alongside each other.