Yeah one of the things with these MP games is that the players stays around after the game ends, which means rep matters and being too evil will haunt you in the long term. Of course, "if you can't enforce it then don't make it a rule" is always a good, when I say good faith non-binding, I guess the good faith part is unneeded and a bit misleading, let actual repercussions do the talking!
The way I see the UW deathmatch situation is that I don't see neither side rolling up the other quickly unless they get some horrendous luck, and likely the ocean won't be unified until midgame or so at the earliest, thats a lot of turns where you have you are locked in mortal combat with an inherent lower income / gem and thereby research. Even assuming all land nations are fighting it out in death matches, they are doing so with avg 22 provinces apiece.
I would
conjecture also that there is a lot of interest from land not to see ocean unified and thereby intervene (god knows I would if I see 2 wounded small fish duking it out) , though only experience can tell, maybe they'll be more preoccupied with Ashod's power or something. Another thing is if you own the whole ocean (or just half for that matter), your looking at bordering 6-8 nations from as the water province placement, though this admittedly could be an advantage (a tough one), whereas an average sized land nation will likely border 3-4 nations or so, with a larger income and potential gem generation.
Getting to land without securing the ocean seems unfeastible to me, land nations will want to kick you in and the other UW nation will make you regret diverting too resource shore side.
Now as a disclaimer, all these things I've laid out are partly to serve as a backdrop for my diplomacy effort in-game (I'm poor, weak and locked in mortal combat, you can drop your guard around me!
), and I've certainly thought out some strategies suited for my situation. In fact, I derive a lot of enjoyment from doing analysis and work out various scenarios and their strategies, the bleaker it seems the more fun it is to plan and survive, so Blackguard stop popping my bubble of black
I just hope I get to the late game at this point!