Poach the eggs, dunk them in a GI pan with ice water. Assemble the muffins and ham and poached eggs, onto a sheet tray, reheat in the oven.
Hollandaise you either make a batch at a time or you make it and store it in a thermos or bain marie. Keep ahead on this. Eggs Benny at a buffet is a two person job.
Alternatively you can add some cornstarch to the Hollandaise. I didn't suggest that.