There doesnt seem to be any ryme or reason behind bulb size and stem and bloom size.
I feed my lilies 2 times a year and they grow well.
I have had occasion to accidntly unearth an asiatic that was large stemmed and many blooms. The bulb was really small.
My philosophy is "if it aint broke dont fix it" so I just continue to feed and admire these wonderful plants.
I dont have the deeper knowlege of plants that some do here but seem to be able to grow lilies.
This info. is for anyone who is a novice and thinks they cant grow lilies.
I am with Connie and the PNW theory.Its just the perfect climate for many plants.