Most powerful reinforcement per faction

• Republic: Commando
• Rebels: Wookie (??)
• Resistance: Spy
• Clankers: Commando
• Empire: Death Trooper

First Order: All of them

Republic: The ARC Trooper

Sepratists: Commando Droid 

Rebels: Ewok(they’re ultra sneaky)
Empire: Death trooper

Resistance: It’s a legitimate tie between the creepy smile lady and the shaved Dr. Seuss creation. 
First Order: Ariel unit. It is super mobile and able to enter and exit quickly. 

Thanks for commenting on this thread!

Republic: Clone commando

Separatists: Commando

Rebellion: Wookie

Empire: Death trooper

Resistance: Ovissian gunner

First order: Sith trooper

Republic: everyone except wookie warrior, commando's tankiness probably beats arcs extra dps, but they're all top tier.

Separatists: tie between aerial and b2 super, droideka can be really good but is very, very situational

Rebellion: aerial

Empire: tie between death trooper and aerial

Resistence: tie between aerial and spy

First Order: aerial is a bit better, but sith trooper still rocks and is a bit better in cqc