I don't see anything SARable happening yet, but that doesn't mean it won't.
It's quite possible that the payee simply intends to deposit those checks in different accounts and wanted to save himself a step later.
It's also quite possible that he is structuring intends to cash those checks elsewhere.
My suggestion is to watch for the cashiers checks to clear, get copies of them, and determine at that point when and how they were used. Once you have a complete picture of the whole series of transactions, then determine if it's a SARworthy event.