I'm not a fan of 'Biker Churches'. I do know of another case where outlaws infiltrated such a group and the subset used it as a cover. That could be what is going on.
I thought it was overkill at first, and maybe it is... but you have to take into account that this was in a very residential area. Set Free owns several of the houses on the street. I imagine some of the overkill was on account of innocent neighbors that could have been harmed if things went south... and perhaps some consideration of the bonus publicity for making themselves look powerful on the news.