Yes i guess leader would be better and save the titles to the in game progress system
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For sub communications there will be a sliding scale from arcade (with transfer of targets and goals) to more realistic (nothing really). It really depends on the people playing what they want. Most games will be played with teamspeak and something like that i think.
The games focus will be coop with players vs the rest. Making a sub vs sub game mode should not really be a problem so it might be included. I will not focus on adding support for playing surface ship but i think it will be possible for others to add later on.