This is an issue in some other faction packs, as well.
For example, in the Enclave faction pack, you can recruit Power Armored Elites, Mr. Gutsies, Assaultrons, and Sentry Bots. When you start an assault, the special recruits section only lists Power Armored Elites and Assaultrons, but under Assaultrons it will show a count of *all* of the robots, not just that one sub-type, and if you send them all, they all still appear on the assault.