Um, I answered your two questions in that post you just quoted.
* Did we need Boyd?
* Should Milf have been moved to fullback to allow Taylor to play in the halves?
Such a backwards argument if can’t organise attack can’t organise at fullback. I would argue other way plenty of fullbacks can’t play half. Different skill set.
Besides organising defence from behind you get a wider view. You need to follow the ball and manage numbers, it’s not the same as creating attack. Same skills he had in attack at fullback follow the ball and work numbers. Getting him confident doing this and talking on field might get in ready for halves in late 20s, not expecting him to be 6 and 7 now.