Boy would I love to see this... In space it seems like a no-brainer that it should be included.
Even better would be a way to integrate the marks with the Away Team... that is, 3 or 4 marks to indicate a kill order which the the away team NPCs would follow, 1 or 2 to indicate CC (ie don't shoot, hold/stun if possible). I feel like adding that fidelity of control over your NPC away team would really enhance the ground combat (which I already enjoy). Also, I feel like that would allow the ground encounters to be tuned to a higher difficulty. Now players would have to approach each group of opponents with the right strategy AND the right execution.