Is Adjustment of fence posts ok

I bought 3’ fence panels and concrete posts, my son intended doing this but now can’t, just got a builder in to do it, and realised as I am having 6” gravel boards, with 3’ panels, the posts aren’t tall enough. He has proposed removing the ‘noggins’ from the posts, to allow the posts to sit 6” higher, says there’s plenty to go in the ground, I can’t see a problem, so long as everything is lined up ok. Does this make sense ?