Form my experience of playing GLA/MRD/LNC around R20-30 with my friends.
I take tanking role, I got problem of holding enmity while in LNC even with skills build for tanking.

I quite assure that LNC isn't suit well for tanking or even off-tank. With their lacking of enmity holding and being fragile.

Diversion isn't skill for tank in my opinion, it just like "Oh! no!" skill that save you from pinch. But I still working on LNC to obtain it for my tanking option.