Speaking to a St Mirren fan today, he said that Miller has been brought in as a sort of Technical Director. Apparently if he'd been given the title Assistant Manager, it would have meant Spalding would have been due a bigger payment. Since they are still paying off Tommy Craig & Gary Teale they didn't want the additional expense.
How true that is, is debatable since it would suggest Spalding was made redundant.
Coincidentally that was how Miller had the title player/coach at Cappielow, since Benny Rooney had been made redundant. Of course he was Manager in all but name, the title being restored when Tommy McLean took over.