It is a joke that got carried through. Who TF cares? Honestly, it doesn’t make a difference gameplay wise at all! Just let a joke, be a joke. Some of the people on these forums can find anything to complain about.

So all our guardians are rehashed...

You didn't mention story. You mentioned an AI controlled character. And by the way, the fans have fleshed out Randall pretty heavily. He's taken on a character of his own, and it's unfair to call the basic fanservice a rehash just because it's a Vandal with high HP. If you don't like it, it's literally one character in one spot in this game. Just ignore it.

The legend himself, Randal The Vandal lives! No need to be a jerk about it. I'm sticking with them for the long haul as a dedicated fan, and I'd like to see something stay in the game the entire way like this.