Farming Mamool with 3 people is really easy. The only way to know which one the correct NPC is is to talk to the other npcs. What the spy says is not unique.
The best way to do it is to find a group of npcs that you think is close to the general vicinity of the spy (based on what other npcs say), and find one that says which direction the spy is, and follow him around waiting for all of the spies in that group to change positions, and keep talking to that same one. What he says will change based on where the correct one is. 30 minute assault, takes about 5 minutes to win and can be soloed.
1200 points for getting the capture right on the first try, 1133 if you capture one wrong one first, I believe it was 1050 if you capture two incorrect ones before finding the real one.
XI Wiki


