I’ve been noticing this lately and I let them have it (they do it by provoking early in the fight). I’d rather not bother with wiping so I back off. In general though, higher HP tanks (which is opposite pre 5.0) just because of natural enmity gain.

Really tanking should be higher ilvl starts. Lower ilvl gives them 3 rotations worth of enmity then turns on their tank stance and both proceed as normal. If main tank ever dies due to a mistake, aggro is on OT without having to hit provoke.