The Vampire Legacy Challenge [UPDATED: 29/1]

I'm looking forward to trying this challenge today, but I have a question about creating covens. Two of the rules state:

You may start a new coven/household of vampires as soon as a turned sim reaches Vampiric Rank Master/No. 4 (Move them out of the active household via Household Management)

Existing Covens/Households must have 5 vampire's in residence before a new Coven can be started.

Say I have 3 turned vampires in my household, and one is a level 4 and the other two are only level 1 and 2. Can I move all three out to a new house/coven or do I have to wait until I have 5 vampires, all ranked at level 4? Or could I move the 1 vampire that is level 4 out and move each other vampire out as they level to 4?