Yes, I thought they were all 4-5 feet because the man across street had them in his yard and the globes were as big as gazing balls and I know they were 4 feet tall.
I was looking at some on the internet and I saw some beautiful Alliums called 'Purple Sensation' and I fell in love but cannot find anyone who sales them.
I would not have considered buying any at all except yours are so nice and not to big. I found there is a lot of different ones out there and some only 8 inches tall.
I really wanted some of the star kind but taller at least 3 ft, and Mary's has one variety that says it gets up to four feet. They are just round balls but would still make a statement, 'Gladiator Allium.'
If this is your Globemasters first year, then it might not be full grown, they might surprise you next year! I would not mind having some of the Globemasters, if I could find the star kind like yours.