Make Stealth checks and when you are ready to strike, make a roll. You get an asset on the attack as the sleeping margr are (likely) unaware of your presence.
Rohim get up to the margr leader, hold both his bow and arrow with one hand and charge the other hand with lighting. He wait until everybody is ready before striking.
Nim aims his Sisk, ready to be thrown at the leaders head at a moments notice. While waiting for a signal to strike he glances at the blanket with odd objects nearby to try and identify them. He whispers to the group. "Let's see if any of these objects might be helpful or at least better suited in our hands rather than theirs. Rhaezon, Aduan, are there any nearby weapons we can relieve them of before they're awoken?
Aduan senses that the objects in the blanket by Nim are the only numenera other than what your companions and you brought.
GM Intrusion: Rohim take 1xp and award another 1xp to a PC of your choice.
The leader, not as asleep as you had assumed, suddenly kicks out, knocking Rohim to the ground and you both roll to your feet, weapons at hand. Initiative rolls please.