Dual Harken will be the tanking go-to Axe without a doubt. There is no debating it, Allagan Battleaxe is just for PvP/Mar DPS purpose only. Also the other ilvl 90 shield is a Lantern Shield, which as previous calculations have shown is good for multi-small hits encounter (WP Speedrun), but still fall short in real tanking situation. Using that shield will net you more DPS via Shield Swipe in the event that you are good on threat.

However there are situation where the ilvl 90 new shield is good. Which are situation you rather guarantee your block and take a slightly harder hit which in my opinion would be somehow good on HM+ Titan at least.