I think no, you can't join IC's to them. This is why: there is a difference between,say, Eldar Jetbike and Windriders. It says, as I believe the Count's quote is exact, units as opposed to unit types. Eldar Jetbike, or Infantry for that matter, are unit types,not units. Windriders, Guardians etc, these are units. A model who has had the independent character rule removed is a unit that always consists of a single model. So no, you can't join IC's to them. This is RAI and RAW.