If you recall Superdoom killed a few supermen in AC 9, one called Omptiman and a Chibi Superman
The chibi-verse is easy
Trying to figure out who the others were. I looked for an Optiman, Iron Knight, Red Racer, & Flashlight and these are what I found. Not sure if I'd consider Red Racer a Flash rip-off not Nor "number 4" a Green Lantern Rip-off like I thought.
Could these just be random names DC threw out or were they referencing other characters, both indie and from other companies?