Here are some more specialist ideas that I've come up with.
Constructive criticism are welcome.
Duke
Local: drillers don't use power
"Managing your resources is a key to success."
Duke -> Lord
Your factories within lord's outpost's sonar range produce +2 drillers each production and generators produce 10 more energy.
"There is no limit in life, but the limit you set yourself."
Guard - 2 units
Local: Add 10 to outpost's maximum shield charge.
"Defence is not for the weak, but to protect those that you love."
Diplomat -> ambassador
Cannot be assassinated. Shows location of all specialists. Gifts towards and from other players travel at 3 times the speed of an ordinary sub.
"Wise words are worth 1000 drillers."
Explorer
When travelling at an outpost hidden from your radar, travel at 3 times the normal speed.
"There is no reason to fear the unknown."