Your proposal is a valiant one, but you are, like many great men before you, ahead of your time. Currently, there are two major problems with your proposal.
A. At the moment, the player base is split roughly into two by allowing PVP and PVE. A further division would result in smaller battles and extended waiting times, less accurate group battle samples and, most of all worse matchmaking. This is something one can look into once there is a stable playerbase big enough to support such modes. Think about it that way, would you rather have normal PVP or random PVP if you only could have one of them?
B.
The way progression is handled at them moment such a game type would not do. As ships tend to do more damage the more guns and higher caliber guns they have, you could not implement a general experience earned. One could implement a certain factor, like 1.5 for snow, 1.0 for trinco or 0.5 for victory. One could most certainly make it work, but only at the expenses of a lot of trouble and most likely a lot of folks unhappy with the progression system. After all, people want to play that shiny new ship they just unlocked and most think bigger is better.