The zone control game has the problem with units obtaining veterancy. For example, the civilian PDs have 600 HP, but that shoots to 2200 when they reach vet1. The same goes (and here it really becomes an issue) for the player's PDs, where the 5000 HP is reduced to 2200 when those reach vet1. The upgrade things in the game reset this, but it is still quite annoying and potentially game-breaking.
I have uploaded a replay in which I let a civilian PD reach vet1. Additionally, I played a bit with the cheats and got the GC and Monkeylord that you get at a certain amount of kills to kill some units and reach vet1 as well. The Monkeylord goes from 500.000 to 49500 HP when it makes the 75th kill.
I am unable to get rid of this bug because I don't really have the time and I certainly don't have the skills to do so. As such, here is the report of the bug.