I'm not certain I understand your question on this Gemara, so I will try to address two separate points.

The actual measurement is irrelevant, as the point of the Beraisa is that there is the same amount of space as the width of camel in between each camel. The width apparently is measured from the left to right side of the animal, though from exactly where is also irrelevant, as the Beraisa's assumption is that it is from the same place, as long as all of the camels and spaces between them are the same.

All the best,

Yaakov Montrose