I was going to post a long-winded mathematical breakdown of the Wheel because the way it was written made me think the bonus increased from +1 -> +2+1d4 -> +3+2d4 but after rereading it again I got it wrong, the d4s just make it apply to different categories and they can stack. The math checks out too. Thought I had sniffed out something broken but it ends up being fine, woops!