I love Armor, Armor, MR scaling, and MS but I mainly play taric. However, I won't lie; I used to run Flat AD, Armor, scaling MR, and flat AD. You have no idea how much taric hurts with a ton of early AD
Carpe Diem, Memento Mori Take my hand and on dark wings we shall fly away from this corrupt place. Together we will experience the world as it was meant to be
I use 21 armor, 24 mr at 18, 3gp10 for tank supports like Taric or Leona. 8.5 AD, 13 armor, 24 mr at 18, 3gp10 for offensive supports like Lulu or Thresh. 9 armor, 24 mr at 18, 5gp10 for passive supports like Soraka or Janna.
Much depends on the AD carry I'm laning with. Sometimes swap out the scaling for flat mr too.