The only caveat, and this is an experience on UA, I am not sure if DL numbers it’s flights like this, is some flights even with a plane change are a single flight number and count as one segment.
in other words XXX-YYY-ZZZ is a single flight number and therefore is a single segment.
UA and I think US both did this. I’m new to DL so not certain it numbers flights like that.
mike