I ran rear panniers on a front rack the last time i was out. Then a compression dry bag atop the rear rack.
Coulda gotten a bikepacking saddle bag thing that sticks out behind the saddle or a carradice bag to replace the rear rack and compression dry bag to save some weight...though not sure how heavy a careadice bag is.
Anyways, i had only 2 panniers but ran em up front and they were large rear volume bags.
Most anything goes if it works for you. Like many other parts of touring, there is more than one way to skin a cat...or to move happily down the road.