Tanking and weapon level sync

[Shalan]

If we're at the point where his enmity bar is about 95% full (missing out on a combo usually means the mob attacks him) would a Flash keep the mob on me or would I lose it before I can pick up the next combo?
And I normally do a full Halone combo on the enemy, just sometimes I switch it out and do Halone if I'm about to lose a mob to another player (sometimes DPS isn't attacking the same target). It wasn't something I had to do often but I put it in anyways.

I should probably add that I didn't lose aggro to him much (the bar was just on the borderline of losing the mob) but the few times I did lose it are a few too many imo. Just want to try and avoid such things in the future to give myself more breathing room.