Toss has air and what is the best of all of em?

[SmashBros.Pro]

Scouts do shit damage to ground units and it can be easily countered if you go all air. Sairs arnt used to often as air support their usuall used to harass Zerg Overlords. Scouts make good support for Carriers and they could help if you make melee ground units only. But you should have at least 4-5 Sairs so you can use diable their units.

 

[Renzokuken]

Scouts + PSI-Storm counter MASS BCs and Carriers.