Backward step

Over the last two tri seasons I’ve completed three Ironman races and a dnf in another .All were completed with the minimum training which showed in the results 16.05 16.32 and 15.53.I jumped to the Iron distance after a few average years at olympic and sprint distance.My question is would it be better to go back to the olympic distance for a couple of years get a few solid results and which I could be proud of .Or should I continue with the Iron distance with a different attitude towards the training nutrion etc.Is it possible to be faster at Ironman without having great results at olympic.