questions of crank ratio physics

[IntoIt]

I play unicycle football on a fifty yard field. Wheels up to 29" are allowed, and that's the size I use. My only smaller option is a 20" and I want more speed than that. My friend who has a 24" with 140mm cranks keeps even with me in 100 yard races whether I use 125 or 145 cranks. It shocked me. I want more speed than him within 30 yards. The equivalent ratio for a 29" would be almost exactly 150mm cranks. I could use more practice with acceleration and startup, but these vary with crank length also. With my 125mm, I spend most of the race catching up, so I am faster, but with these short distances, it doesn't matter.

How should I maximize acceleration within these parameters of distance?

That is, should I ideally have even longer cranks than the equal ratio of his crank/wheel simply because my unicycle is bigger?

How could I calculate something like this?

Also, if anyone has experience racing, and has used a 29, or just if you have tried this stuff, what is the fastest way to mount (and by 'fastest' I mean most conducive to immediate acceleration)?