Geoff isn't a parkour guy and has said that Stage 1 is just not built for him. I think if he ran all four stages 100 times, he'd do better on 2, 3, and 4 than he would on 1. Rosen, Dory, and Bull are better built for Stage 1 in my opinion.
I would be tempted to say Geoff, but I'm actually going to go with James McGrath. He is strong enough to beat Stage 3 but has failed the JS two years in a row. I'm surprised he didn't nail it after falling there last year.