Originally in the earlier euro days , heavy armour did have dc0-2 as well as iron having dc0-4, and medium armour being an in between armour.
iv never fully understood why these changes was made along with others like the renaming of bosses such as evilcentipede to bigcentipede and whiteevilboar to whiteboar.
The removal of DC on Warr armour was because it made stat requirement gear too easy to get on (Skele, BIH etc) so they removed it to make it a little harder.
Also in the process made Med armour like someone already said a noob rare, with the downside being dura (Although I'm fortunate enough to find a D.18

)
As Med was never a shop item it was hard to come by, and some struggle to even equip cause of its weight
The mob name changes I couldn't tell ya....maybe cause it was obvious these things were "evil"? But then the same could be said for the "big" centipede lol
Could also be an over use of evil?
EvilSnake...WhiteEvilBoar...EvilCentipede...EvilTongs...RedMoonEvil
Perhaps they wanted to change some lol, was a little repetitive i guess haha.
Maybe you guys should keep that in mind when you implement? :P