Also consider that, if you're approaching a group of enemies that are all relatively close together whether or not you have any intention of moving them from where they already are, you're usually better off running right into them and opening with Flash simply because that one Shield Lob on a single target means next to nothing when you're left waiting half a second or so to come off cooldown to aggro the rest of the group for what has to be a Flash anyways. Not that it really matters unless you're teamed up with people who don't wait for you to establish threat, but just something to consider. Albeit, if aggro itself is proving to be an issue rather than your method, then perhaps that extra aggro on a single target might be worthwhile at lower levels. Once you hit 26 and get the third part of your enmity combo everything will be so much easier.