I think the reason there are three prize pools is because a People's Vote can turn into a popularity contest at times. I also do indie comics and when awards, contests, or Kickstarter seasons roll around, people who have these massive pre-existing followings (which, fair enough, they've had to build up in the first place) just dominate. People blindly put their vote in for their favourite person out of a sense of loyalty and it quickly stops being a qualitative assessment.
Sadly, the only recourse is often to fight fire with fire. Tell your friends, family, Twitter, Instagram, etc followers that you've entered, ask them to give the game a try and, if they like it, give it a rating. I think that's the key thing, asking them rather than telling them. In the comics world I've seen some shady tactics where they've said "Oh, vote for my comic, send me the proof, and I'll ping you a free copy of this other comic I made!" or offering a free sketch or what-have-you.
Fingers crossed, everyone plays a clean game here. That said, there are already some entries that'll get disqualified for breaking "Development on contest entries MUST be started after the beginning of the contest (October 29th, 2018)." (mostly games that seem to have been submitted for multiple jams scattershot without thought to the rules or relevance of each jam rather than games that were tailor-made specifically for this jam).
Time will tell. For now we have to trust the team behind the contest and let them do their jobs. :)