Speed is a really important attribute, not only because it decides the attack order, but also because if you are faster than the enemies stunner, you will be immune to his stun. Therefore, speed is the most important attribute for Scholars, since if you are too slow, your stuns will have no effect (the stun effect is applied, but is removed as soon as it's that character's turn.
You can increase speed with boots, fruit, evolutions, levels, bonds and food.
The fastest 6 T1 characters are: Awakened Gol.D Roger, Awakened Sengoku, Doflamingo 2Y, Gol.D Roger, Goro E and Blackbeard.
The fastest T2 characters are: Doflamingo, Aokiji and Hancock.