Quote Originally Posted by Efrye View Post
By using the damage done by the dragoon, and subtracting 10%.

Obviously the 10% is just a random value, and it doesn't really matter either. It could be 50% as well or whatever they feel is appropriate - the total dragoon damage would always stay exactly the same. (Unless you want a small random factor in the wyvern damage to make it look less predictable.) That's why I called this solution only visual, there would be no real pet damage.

Travel distance shouldn't be much of an issue either. They are flying after all, a quick dash before the attack should do, and they can stay close to the dragoon at all times. I guess their attacks could also land a second or so after the dragoons, giving them time to catch up small distances.

In other words, all the issues you mentioned appear to be easy to avoid, as long as you treat the wyvern as a visual element, rather than an integral part of the gameplay.
In PVP...

Your Enemy: "HUR DUR. *One-shots Wyvern*"

You: "Aw, crap. There goes 10% of my DPS."

One reason why I don't want a wyvern for Dragoon.