The only way up to them, without going 100s of meters out of the way (which would give them an opportunity to try to flee if they are so inclined) is by the same dog-legged route that you watched them take up to their current position at the top of the out-cropping after they first spotted you.
And because of their significant height above your path - nearly 10 meters - you cannot possibly maintain visual contact while also ascending to their position.
But Duinhir's watchfulness prevents you all from being surprised, as pebbles begin to cascade over the edge above you, and both travelers come to the edge with large rocks held aloft over their heads to cast them down upon you.
OOC:
So they're up on a cliff and because of the steep incline you have to zig zag your way up. Which means you must pass below the cliff once to wind your way up to their position, and really there's no possibility to see what they're doing once you're much closer to the cliff.
But to reward Stefron's good roll, and all of your general suspicion: there would normally be a surprise check for each of you, but because of the crit success, none of you will have a chance of surprise.
Initiative!
