Grumbot Prime isn’t “Grumbot” and is instead Mumbot and comes from a timeline without Grian
Evidence:
Grian brought Grumbot Prime as a replacement for mumbo
Grumbot Prime lacks a fringe which is the only trait linking og Grumbot to Grian
Grian could have been the reason that Mumbo lost in the og timeline which is why Mumbo won in Grumbot Prime’s timeline.
I hope this made sense, it’s abit of a stretch but I noticed this and thought I should share.