Yei know whats weird with this one you are with 8 instead of 6 it can be done if you do the run form ToA to this mission (not sure of the name think Divinity Coast).
On first glance I am going to say there are 8 people in the party when Sanctum Cay is a 6 player mission. There is also probably something wrong with the N/S/E/W directions on the map and with the mission text, but I don't know for sure.
I think Scorpion Boy is correct. If you run from ToA (which allows you to have 8 players) to Sanctum, you will retain the 8 players that are in your party. This gives you two extra players in Sanctum.
I'm going to to the same soon, but then a little bit more extreme. What I'm going to do is run from Dedrimor War Camp all the Way to Ascalon City Last time I made it to Yak's Bend, but it got a little bit boring
you can go from toa to ascalon but not the war camp, you need to pass through beacans and it will resset the hench, if this can be done nother way please enlighten me.