This is a nerd game, so I'll bring math into it... If you randomly select from [0,2,5], the standard deviation is 2.05. Randomly selecting from [0,4] has a standard deviation of 2.0 and 3p is actually more important than 2p. So if the goal is to best approximate perfect equality of 2p, 3p, and 4p, the current design is as perfect as it gets.