You certainly are lucky to have so many pups, Andy. I would separate the pups when they are about a foot tall. It's harder for the smaller pups to survive the transplant shock. It takes a while for the pups to establish some root system of their own. Furthermore, the mother plant is still very tender at the height of 2 ft. Give everything some time to grow bigger and stronger first before the transplant.

Are you going to leave your basjoo out in the Winter this year? I know they are cold hardy and will come back in the Spring, but I don't know down to which planting zone.

Bananas do like soil with drainage. They can be watered heavily to promote growth and then allow time to dry out before the next watering. If you can dig out some of the clay around it and pour in some potting mix mixed with some pine bark mulch, maybe that might help the soil to drain a little better? They also like a layer of mulch to trap in moisture on the ground cover.

Hope all goes well with your family of basjoos!

I have removed them from a few inches to a few feet larger is better,you just need to make sure they have there own roots or they won't make it.