The gear gap is very large when you look at optimized aug wh. Just a fotm example for you is that an optimized aug wh jug's smash will do more than twice the dmg of a recruit jugs. Add that to the much larger dmg mit, and much higher health pool and your 20% figure is just beyond ignorant.
So much this. Even if you'd make it 20% both for offense and 20% for defense, that ends up being a whole lot in the end. Hopefully when Gabe said that he wanted it to be 20%, he meant a combination of offense and defense.
By the way, where the "20% PVP gear gap" came from was an interview from a few months ago. Gabe said that they eventually want the gap to be 20% going from a fresh 50 (which I would assume means Recruit since it's free) to someone in best gear, but they weren't there yet, and that they were going to introduce Recruit MK-2 but that still would not bring it close to 20%.
What was going to bring the gear gap closer to 20% was the planned gear bolster for level 50, which we unfortunately haven't heard anything about since.