The reasoning is nice but the names are terrible.
Oak is passible, I suppose (after all
Rowan is a perfectly fine name) but I can see teasing ahead (using my dirty schoolboy mind I can forsee references to logs and twigs dependent on how well-endowed he is along with 'hard/strong/stiff as a oak' etc). Harvest is just plain daft, at least though he can go by
Harvey to hide it. Oak has nothing.