Found out that this unnamed LEGO Arc Trooper is actually a named Clone in Season 3 episode 2 (“ARC Troopers”). He is seen for a few seconds and goes by “Hammer”. I
Hammer (ARC trooper) | Wookieepedia | Fandom
I finally got my hands on Arc trooper Hammer! It will make a fine addition to my clone army I'm building. : r/legostarwars
ARC Trooper - Hammer | Star wars pictures, Star wars images, Star wars commando
Lego Custom Star Wars Helmets Clone Army Customs Arc Trooper Hammer Helmet