Well the season is 3 games old at this point. Not much data.
That said, I assume Rob will generate the same DC success his brother & dad have and that will result in HC offers. I'll suppose again that the relative success his family has had as HC's will follow him as well.
All those qualifiers to say this. I think the Wade/Garrett situation has revealed a dynamic often overlooked. The HC, and the climate he sets, can either help or hinder the coordinators and paint a false picture. Maybe part of why some successful coordinators fail as HC's.
Rob will probably succeed at both, DC, then HC. But its early.