In the test cases where there are 1000 elements or more in the data array, the max number may not be unique. For example, if the max in the array is 1000, there can be multiple 1000s.

This raises a question about how we should deal with the existence of multiple max numbers:
Should we take them as just one element?
Should we place the group of max numbers in the middle, and then arrange the rest of numbers in the mirroring fashion?

Moreover, we may have an odd or even number of max numbers. Under the requirement of returning an array with an 'odd' number of elements in it, things can get more complicated.

This possibility of having multiple max numbers and how it should be handled should be mentioned in the description, and the test cases may need to be reexamined as well.