Both of them are great, but I'm also gonna say the old one looks better. Considering most people will be seeing your thumbnail on the front page/fresh section/everywhere else besides your actual comic (especially if you have a banner for your comic, meaning your thumbnail won't show up when reading your comic) you want to make sure it's going to be simple, as it's gonna show up a lot smaller than it does usually; having that many characters in one shot (even if it's only three) might get too cluttered for readers to be able to make out at first glance.
Hell, if you take the text out of the new thumb and center the image, even that would be better IMO (the title being in the thumbnail is not super necessary either, but it's a preference thing).