What the game engine considers "Partial plate" is what I've always known as plate & mail. Venetian heavy infantry starts off in half plate, steel cuirass (front and back) plus a visored helm, but no arm or leg protection. Upgrading them with the "partial plate" level changes their in game representation. They no longer wear the visored helm, it looks more like a mail coif. But they are also wearing a full mail hauberk with a surcoat or tabard over it, steel plate greaves, vambraces, gauntlets and boots. The overall protection level would be considerably higher. Technically, the first upgrade for Tercio pike was light mail, I think, and heavy mail was the second. The first one showed them in the same basic setup sword & buckler men had, colored clothing with slashed in it where the mail would show through. The second was half plate, the helm and cuirass, though they did have tasses hanging down to protect the upper thighs. I don't have a problem with that part of it.

Where I have the problem is the same place Dopp has with it. It's half plate! It should give an armor rating of 5, and instead it gets a 2. That's a massive difference, especially when facing missile fire, and the casualty rate is significantly higher as a result.