The term translated as whole number
can mean parts.
This may therefore be pointing to a tribe with different factions within it. The members of the spy team may well be from different parts of the tribe, and thus be representatives of the different points of view within the tribe. These are called upon to work in harmony with each other, to fulfill the mission given to them.1
2 So the people of Dan sent five able men from the whole number of their tribe, from Zorah and from Eshtaol, to spy out the land and to explore it. And they said to them, “Go and explore the land.” And they came to the hill country of Ephraim, to the house of Micah, and lodged there.