At least it is now better than when they have not changed it, it was for 20 winners before they changed it to 10 winners 1-2 days ago. Nothing they can do with the adjusted prizepool. $1500 can be ideal to be split between 5 winners but it will make others losing hope for smaller prizes. If I am standing in the casino position, what they have now is the best option already.
I know why you are happy with the changed reward distribution

. And I do agree with you on the point that the $1.5k is ideal here to split between top 5 ranked users. There won't be any tough competition for the 6th to 10th rank prizes. The reward has dropped by $10 on each rank from the 6th to 10th rank. I believe no one will compete (do wager) to achieve any of those ranks. Anyone with the wagering plan will compete for the top 3 prizes only.
Only 10 will share the $1500 in the contest? It seems like it would be even harder to be among those 10 winners. It seems like 20 winners would be even better
so that at least many people will have fun at least in those event games.
Maybe the other players instead of participating will not participate because the chances are even lower, of course out of 10 winners to be chosen, it's hard to be among them,
so it's just a matter of luck.