Speed pb with young han solo

His offense carries through phases, unlike Ventress.

You will lose those stacking boni when you switch phases. Its the same with Ventress.

Prepared has nothing to do with it. It's his first special that gives him speed. And the speed resets between phases.
With that said, I also feel like he doesn't quite have that much speed. But it's just a feeling, haven't got any evidence.

like others have said, it's his non attack special, Upper Hand, where he tosses and catches his dice, where he gains the speed.

While it can be hard to pick out in a field of 6-10 characters all taking turns, I've definitely noticed the difference. When you underestimate the bonus speed and Solo loses Unbreakable Will (or whatever the p1 buff is called) before annihilate it's rather hard to miss