Scavenger and the Constructicons debuted in the Transformers cartoon in the first season, presumably having been built by Megatron. (Later on, they would supposedly have built Megatron whilst also having been brainwashed by himself, but they're other stories for other times) Their main enemies were the Dinobots, who don't combine and never will, ok? Ok. The Constructicons DID combine though, which was their main gimmick. This resulted in two things. 1. the toys suffered from the gimmick 2. the characters suffered from the gimmick. Basically, neither the toys were much cop, and the characters were never explored fully, because their combining was what made toy sales. Sad but true. So even though the Constructicons had disparate personalities, in the cartoon at least, not much was made of it. Which missed the point a little bit, certainly with the 'character' (if it can be said that he even had one) of Devastator.
As for poor Scavenger, he got lost in the mayhem of toys to be sold. I always did like his Tech Spec bio though, and imagined him to be almost a giant puppy, always bringing back worthless items and getting reprimanded for it by Megatron and Scrapper. Like I said, poor guy. One day I'll get round to writing his story. Although not for IDW. It might be a smidge late for that.
Scavenger is my favourite Constructicon. Why? Well, because he's the underdog. He's the guy that gets picked on all the time, and I always hated that in any form. I guess being a guy that got picked on all the time at school made me always root for the little guy. Even if the little guy is a 20 foot tall robot who transforms into a construction vehicle.