Yup, they should take 15% more damage from CBows now (25% vs ranged replaced with flat 10% defense), but also be slightly stronger vs other melee, and do more damage.
Not sure if the zeppelin line would stick around to ever seriously be considered as a must-have, it's very awkward. But, at the very least it solves a strange corner case, which is that no unit in base VP can take an incan city surrounded by 6 mountains. All units that can hit over mountains (artillery/indirect fire), or ignore terrain (base VP zeppelins, helicopters, aircraft) are all ranged and can't take cities. So there is at least 1 melee unit in the game that can deal with this unsovable corner case by being a hovering unit with a melee attack.
I'm midway through a playthrough with my Zulu changes (I just reworked 1 of their 4UC components), and my goodness that's a lot of flank damage on swords with Sidearm and Buffalo Horns. It's silly to get overrun on top of it all, but it's just so irresistible.