Getting my family a residence permit

My family is moving to China for my work. I will be living over there for a few months before them. I'm in the process of applying for my Z visa and then the work/residence permit. If they travel over there on an L visa can they then apply for a residence permit assuming we submit all the required documents (marriage certificate, birth certificate, etc) or do they have to apply at the same time is me? My only concern about them applying at the same time as me is that a medical exam is needed within 30 days of the application and they will not be in China for several months after me.

Regards,
Dave