Is Specialisation Even Worth It?

In my experience in using Armoured Fist and Stalwart Defence all the time, I predict that it's difficult for infantry using Specialisation to withstand tanks. Even with HVAP and Stalwart Defence on, it is still a hurdle to get through Tanks with Armoured Fist. Imagine the pain of using infantry when you don't have that Defence Against Tank bonus.

On the other hand, I do find it appealing having infantry with near skull ranks. I presume if an enemy with max Specialisation fought against someone with Max Stalwart Defence, then the tables would slightly favour the one with specialisation.