Yes, but once you have a Windows network to the point where anyone can sit down at any workstation, with all user data being stored on a file-server, you no longer have to back-up the user workstations.
I managed several networks of between 50 and 200 workstations, each with a single Samba-based DC and file-server that was backed up off-site via rsnapshot. The workstations were imaged via FOG. Once we had a working image for a workstation (which could take a couple of days to prepare from scratch), the bottleneck in deploying workstations was physically putting them in place and hooking them up. We could image forty machines in about 25 minutes. Best of all, we could reimage machines remotely. This meant I could set up forty workstations on a Friday afternoon, register them with FOG and deploy an initial bare-bones image, then head back to my office to fine-tune a new image before redeploying it (from my office). Active Directory took over from there. If a workstation started acting up, we could trigger reimaging remotely, and 7 minutes later the user had a fresh workstation.
In that environment, rsnapshot worked fine backing up about 8TB of user data from about ten Samba servers over a 20Mb/s WAN. Nightly back-ups rarely took more than an hour. Storing many snapshots (7 nightly, 4 weekly, etc.) didn't have much of an impact on the required backup storage. It was also nice that rsnapshot could run a script on a server before and after backing up. So one could dump a database to a file before backing up.