The Ending A Little Over The Top

I enjoyed this film, but I thought the ending was kinda overkill. I understand Sizemore had *beep* up there business a lot etc by destroying the peace and they wanted him dead, real dead. And in a way to perhaps send a message. But was it really necessary to have 7-8 guys shoot him at the same time? Is this realistic of gang executions in any way? Or did they just really over dramatise it like I'm thinking. There were 2 or 3 tek9's used aswell, presumably they'd then have to ditch these or face the possibility of having a cop's murder pinned on them, if caught with them. Seems like a waist of some valuable weapons to me.