Having no enmity on some of the enemies is fine as long as your healer isn't a spaz who heals you before you're done the pull. Stopping to hit everyone is either a huge TP sink (lobs) or will make you eat a lot of unnecessary hits and make you need heals before the pull is done, kind of a self-fulfilling prophecy.

You can Thrill/Second Wind near the end of your pull to throw out a bit of aggro on everything you've pulled too, it's something that will ward off Regen aggro.