So, I have some ideas of new boosts (because your not thinking of only having 2 dont you)
Sniper boost (I sucks at making up names)= A boost that just takes out two enemy armies in the same region (Only 1 if its a 2:er region and none if its a one).
Spy boost= makes the army count of one of your regions invisible! You can still see it thought.
Portal boost= makes you be able to attack a non bordering region from one of yours.
Indestructableness boost= makes one of your regions inattackable until its your turn again, then it disappears.