I've had two varieties that did the 'twinning' thing Lynn - Saga, and Ruby Heart both have a couple of chicks that are like this. It's like conjoined twins, maybe they can't be surgically separated.
Here are some Whirl-i-gig clumps - they are so ugly. The tall stem is half rotten inside where I ripped it open, and there was even a tiny slug inside it! These rosettes never seem to bloom, so these are really old, like about four years at least.
The smaller rosettes are better, but tiny (each of these is max half inch across)
Fuzzy Wuzzy has variable cresting, some chicks seem normal, others have the crests. It's about 50% of each right now.
This is Ruby Heart with two twinned rosettes, and Saga (bottom pic) with one. These also don't seem to bloom.
