I'm kinda torn on this. 1. It's definitely not the type of thing Jay would say (and I base this on the fact that he's always been my favorite Flash and I will read anything he's in, no matter how much I hate the comic he's guesting in) but 2. All he's really suggesting is something I used to say a lot "Overkill is the best kind of kill." But I'm a USMC veteran, so YMMV.
Anyhoo, it's great to see Dr. Fate, no matter how much Willingham's dialogue doesn't fit (my perception of) the team.