Why is Phantom Chica based off normal Chica from FNAF 1, when both Phantom Foxy and Freddy are based off the Withereds from FNAF 2?

This has bothered me for a while now, and I want an answer (also I didn't include the other phantoms, because those are just dead-up based off animatronics from FNAF 2.)

This has bothered me for a while now, and I want an answer (also I didn't include the other phantoms, because those are just dead-up based off animatronics from FNAF 2.)