Focus on parts per panel, not arrays per panel
Array material is waste material. You're paying for the part on the array, not the array, so focus on how many parts per panel you'll get, not arrays per panel.
Compare these two arrays. The 9 part array is actually more efficient than the 10 part array. Because the 9 part array uses the manufacturing panel more efficiently, it yields 9 more parts per panel and more parts per panel leads to a lower PCB price.
Part size: 1.0 x 2.0
Panel size: 18.0 x 24.0
Minimum borders: 0.75