IIRC Kicad does force a schematic part pin ID to a footprints ID.
But these don't necessarily have to be numbers.
eg. A Mosfet Part (component?) can have pins marked G, D, S. (instead of 1,2,3)
then the Footprints can have G, D, S too. As long as these match. Otherwise the pad doesn't get a net.
This is useful if you haven't decided whether to go SM or TH. as I think the pin numberings are different on FETs between these packages.
Obviously you cant match a component marked 1,2,3 with a footprint marked G,D,S.
Hope that makes sense.