That's not correct according to Microsoft. Clearly Altiris is middleware or "multiplex" as defined by the document I referenced above. I recommend per processor licensing for SQL servers since so many SQL databases are representing middleware systems like SharePoint, Altiris, Symantec Endpoint Protection, and other systems. Any time clients report data to, or users submit data to, a server running web functions, which then turns around and puts the data in the SQL DB, this is middleware or "multiplex" according to Microsoft, and each client reporting data or user submitting data requires a license.
To avoid this enormous mess we just use per processor licensing.
All this being said, you could choose to do per user or per device licensing. If you want to see which of these three options is cheapest, you can do the math.
For example, suppose you have three SQL servers, each supporting SharePoint, Altiris, and SEP. Your older SharePoint SQL server is 2 dual cores, your Altiris SQL server is 1 eight-core, and your SEP SQL server is 1 quad-core. You would need 4 processor licenses for your three servers.
Then suppose that you are a manufacturing firm with three shifts, so you have 300 workstations/servers but 700 employees. There are no mobile devices. Here you could have 300 device CALs total (device CALs are valid for all SQL servers in the environment) or 700 user CALs. Obviously the inverse could be true -- you could have an environment with 100 employees but 200 devices, since they all have mobile devices.
With these numbers in hand, multiply your processor cost by the number needed, and extend the same for device CALs and user CALs. Then choose the least expensive, keeping things like expansion plans in mind.