I think there is a fourth and forgotten style of Scrapper.
The Evolved Scrapper (Scrappus Evolutios) - This type is often mistaken for any of the other Scrappers as they tend to show a behavior pattern similar to that of their peers. This rare breed has evovled from his/her more primitive beginings. The may have started out as a Wild Scrapper, running rampant through the city obliterating all in their path. But somewhere down the line they ran into something bigger and badder than they were; usually an Arch-Villain or a particularly difficult Elite Boss. This forced the Scrapper to take on teams when the odds were not in their favor allowing them to evolve from a Wild to a Feral demeanor. This however, is generally the end of the evolutionary cycle for these Scrappers as the call of the Wild still pulls them into fits of soloing for hours against enemies they would not have fathomed engaging before. But, in some rarer cases, it has been known for a Scrappus Evolutios to evovle into the Civilized as they become less comfortable in the wild and more comfortable around others. But, they will still be prone to heed the call of soloing from time to time. The Scrappus Evolutios is the most likely to form a permanent duo relationship that will foster a family like bond. The duo is unlike the long-term duos most Ferals and Wilds will take on, but one that pairs the two together for the majority, if not all of their careers. This can be anything from a supporting Defender, the long range assistance of a Blaster or even a Controller to better help the Scrapper "do what they do best." In this scenario it is common place to allow the "lesser" AT to terminate the Scrapper's targets allowing his "family" member to feel a sense of self-worth and accomplishment. If anyone teamed with the "family" takes the liberty of doing so, it is generally frowned upon yet tolerated. It is rare for the Evolved to take on another Scrapper or a Tank into the duo as there will be a constant battle to prove dominance over the other which can cause a sense of contempt or belittlement by the adopted.
NOTE: The danger in this adoption is that whatever AT or build joins the Evolved will begin to take on Scrapper-like tendencies. Behavioral patterns include, taking on groups alone, dashing off as soon as the AT is ready and most commonly is the AT will adopt an attack heavy build trying to match the Evolved in fighting capabilities. This can result in serious injury or death of the individual. This will often times send the Evovled into a Savage fury where they will attmept to obliterate all enemies around their fallen family member to allow a revival OR the Evolved will do the same to every enemy within the area before his family member returns from the hospital.