There are two principal issues to consider with this kind of small office/home backup setup:
1) Integrity/safety of data, &
2) Availability of Settings for a Machine Restore
In a business, both of these will likely be critical - included in your settings would be the ability to send/receive mail, and a copy of client contact details. The core business data obviously has utility in itself, but might typically be accessed from a multitude of devices.
At a very basic level, iCloud may be sufficient to restore the basic usability of a new Mac, and other online services may cover sufficient data storage for your needs. However it would not be wise to rely on these.
I prefer to take responsibility for backing up my own data, and do this with a NAS at home, replicated to another NAS offsite. This gives me redundancy for hardware failure of single/multiple drives and, with offsite, also covers major disaster type incidents.
The brand of NAS that I use can be used for Time Machine of individual Macs, and also backs up iOS photos automatically to avoid using iCloud for that purpose.
I would however recommend that you always have an external HDD backup of your primary partition of your main Mac, and for good measure a bootable (CCC) clone.