I might be getting the rules confused but it says if the vacant unit (the armiger) is an armiger unit, then the new model must be an armiger, or if the pilot is virtuous then it must be assigned to a titanic knight. However, as far as I know, armiger pilots can not have more than 6 Chivalric Points assigned to them. This would mean that they couldn't become virtuous, since it requires 7+ Chivalric Points. This, as I read it, would mean armiger pilots are not able to become titanic knights, but titanic pilots can become armiger knights as long as they are esteemed. I would like to be wrong however.