Add "customer group" as a parent of "customer type"

It would be great to have the ability to group multiple customer types together in a customer group for which rules, price calculators, and dynamic front end merge codes could be made.

For example, I have a dual purpose retail and wholesale store, but I have multiple types of wholesale customer types which have their own unique configurations for shipping / payment options and product availability, but they all share the same wholesale pricing calculators, which also need to show a different price to retail customers, making for a lot of duplicate price calculators.

because all of the configuration settings for anything related to customer type only allow a single customer type to be specified, it creates a lot of clutter and in some cases completely limits my ability to configure the store the way a multi-vendor multi-customer type store should be able to be configured. 

An alternative, and potentially easier?, solution may just be adding the ability to select multiple "customer type" wherever configurations can be set at the customer type level, either via an array of check boxes, or a multi-selection dropdown.