All AD team comps are not punished AT ALL

itll hurt when you attack them... till clearvers start stacking up and botrk starts melting... but yeah, tanks dont have nearly the power of adcs

Cough Cough, armour and armour pen. Cough

Played Sej against a 4 AD 1 AP comp with two ADCs. I got over 1000 armor with my passive and when it was gone still had about 450 armor. Getting shredded put me at maybe 240. You just have to stack more armor. Sejuani, Malphite, armor scaling tanks. You get both Glacial Shroud items for 40% CDR and mana, DMP, Tabis, Thornmail, and depending on what you like Randuins or Sunfire. I went Sunfire personally because I like the extra AFK dot damage. The key is that you need to stack more armor than they can shred.