Nice post November - I know what you mean, it's hard to 'sneak up' on two elite warriors in an enclosed room with only one entrance!  My GM side says tough titties but my rper side says I was thinking Marko could have smoke bombs or flashbangs to use.  Maybe not 100% sneaky but they'd disorient the guards and put the initiative in your favor, and totally be up a rogue-ish thief's alley.