I know that is a silly question but some cultivators have 20 blooms and some have only 2.......
and in my front bed.... Garden Pleasure grew to be about 6 feet tall and yet ones in the same bed and the same age bulb......grew about 2 feet or a bit more....
I have to wander what causes such a difference...........
the bulbs are the same age and you can see this in lots of beds.........some have 20 blooms and very strong and tall and some are much shorter is another bed and both on the same side of the house and same soil but a bit different location........

Some cultivators likely are known to have more blooms as well maybe. Leslie Woodruff is blooming and each plant has at least 20 flowers and one plant is in a different bed.......and same height and so on this time. It is one huge strong lily.........

Different cultivars will have different heights. Their genetics in each individual lily are what gives it its own unique characteristics. Often newly planted lilies do not reach their true height in their first year, but rather they will the following year/ years after planting.

Interesting.
What I found was rather odd is how the one plant is 6 feet and the same year bulb is 2 feet not that far away from the others ones and in the same soil. The bulbs were bought at the same place too......so hopefully this rights itself next year......hope so anyhow