I wouldn't worry too much about the rhizome size. After a couple of years in your garden they acclimatize to your conditions so the increases will size themselves to best survive in your area. Down here where it is humid and hot in the summer the increases don't stay fat, but become longer and thinner. I am sure it helps them dissipate the heat better, and makes them less prone to rot. In your area they may stay fat to retain heat. You will find out soon!
Traci I think you'll enjoy this forum. Lots of nice and knowable people on the forum too.
traci, and we have fun here, too.
Traci! 
......I'll give you a typical male response...."size doesn't matter". As was stated, they will "seek their own level" after a season in your climate / growing conditions. The only issue, the very large "west coast" rhizomes, when planted late , in more northern climes, often have a tendency to "split open" during their first freeze.....sometimes it's wise to "mulch" with something *loose* (that won't pack down...like pine straw.or even pine boughs) AFTER the ground has frozen ...then remove the mulch in early spring.
Traci.
Tracy
