Apple Time Machine, Drobo and studio computer
I have a similar environment here. 

I would split the task into 2 distinct parts.


For changing content, excluding all sample libraries etc. set up a Time Machine; internal, networked, AirPort Time Capsule or NAS-type. To keep any depth of history you will need a lot more space on the Time Machine than you have on the used drives.
Copy the static content directly to new drives, keep those offsite.


I would then invest in Backblaze [or similar] to backup the entire studio machine. It will exclude 'system' &amp; only backup 'data'. BB accounts are per seat, so you'd have to consider whether the MacBook needed that too.

This would allow you to no longer worry about the mass of unchanging content you acquire &amp; concentrate on the system &amp; project backups. I would also periodically clone the project drive &amp; take offsite.

There's an article on NAS compatibility for Time Machine here

(I don't use NAS myself, I just Time Machine to one of my internal 2TB drives for on-site, short-term backup. I let Backblaze do the heavy lifting, plus physical offsite for projects &amp; sample sets etc.)