I obviously can't tell you how YC will respond to your video, but I find it very unlikely your accent is incomprehensible if your American cofounder said it was fine.

Here's an example from the site I linked before that I would consider completely comprehensible: http://dialectsarchive.com/russia-5

This, on the other hand, is probably pushing the limits the comprehensibility: http://dialectsarchive.com/russia-13

If you fall closer to the second example, then American English speakers may have trouble understanding you clearly, but if you fall closer to the first, then I can't see anyone having a legitimate problem understanding you.

But again, I'm just trying to address actual comprehensibility issues. I can't say whether YC will respond positively or negatively.

I'd divide the time between you both.