Thalassicus
Bytes and Nibblers
I thought of Marine too, but as you point out, marines are part of the navy. The generic name doesn't bother me since all units are generic like "sword man" or "infantry". 
The concept I'm trying to go for with Vanguard units is what's stated in the "Purpose" section: personnel deployed at the front of or ahead of the main army. While special forces sometimes fill this role, not all personnel in this role are special forces. It's like the "all squares are rectangles, but not all rectangles are squares" analogy. This is why names like special forces, paratroopers, commandos, or such don't really fit the concept.

The concept I'm trying to go for with Vanguard units is what's stated in the "Purpose" section: personnel deployed at the front of or ahead of the main army. While special forces sometimes fill this role, not all personnel in this role are special forces. It's like the "all squares are rectangles, but not all rectangles are squares" analogy. This is why names like special forces, paratroopers, commandos, or such don't really fit the concept.
