Thief+Engineer = You gain their drillers, as well as repair your fallen ones, allowing you to keep damage to an absolute minimum. Since Engineers repair after combat, that means you are repairing the drillers you stole as well. This allows you to easily snowball through your enemy!
Thief+King = The Thief did damage depending on their force, now deal additional damage from your force. Even if your force is half of theirs, you can win the battle (Example: player A has 50 drillers, Thief, and King. Player B has 100 drillers. Thief steals 15 drillers. (65 vs 85). King deals 1/3 of 65 rounded up = 22. End of specialist phase player A has 65 and player B has 63. Player A wins!)
Thief+Diplomat = same concept as with General+Diplomat. Send Thief alone at enemy and have it come back. When under 60 enemy drillers, not as effective as general, but over 60, and this combo becomes the same if not more powerful than a general!
Saboteur+Diplomat = Endless defense. Send Saboteur alone at enemy sub. Unless they get an assassin or navigator, you can keep your base indefinitely defended, as your Saboteurs just return back. The fact that you get 2 means that the enemy has it even harder to take it over!
Saboteur+Assassin = Giant combo sub coming at you without an Elder? Just send them a Saboteur+Assassin if you have no martyrs or double agent on standby. Effectively buys you time to get drillers where you need them as well as weakening future attacks by getting rid of their specialists. Oh, and if they try again, you have a second set too.
So what do you guys think? I'm gonna add these to the wiki if no one finds any flaws with these. Otherwise, share your combos!