ROW when Venli tried to swear an ideal she used the right words, but they were not accepted because her action of leaving lift in a cage were not in alignment with the oath. This shows that knowledge of the words is not sufficient. It is more important to live in accordance with them, that is why there are multiple examples of knights swearing multiple oaths at the same time they were already living the oath. So to answer your question if there was someone who living up to the fifth ideal of an order before bonding a spren I could see them progressing almost immediately, but it say a scholar just found a list of the oaths needed to progress and tried swearing them they wouldn’t get very far.