Behavioral changes can only do so much to lower ApoB. It is a meaningful marker and may trigger additional workup. It may also signal that you should at least consider a statin.

ApoA is completely out of your control and will not change with behavioral modification.

So, no, you're incorrect that these tests are superfluous and all you need to say is "diet and exercise". Besides, even if that was always the answer to these results, you should still have a baseline to see if behavioral modification is doing anything.