Software vendor "Support Engineers" usually have very little knowledge of SQL Server (just like their developers and system designers :(), but love to spout nonsense to deflect problems with their software.

Unfortunately, the incompetence of software vendors is often expressed most disastrously in their database work.

I have seen exactly one vendor database out of many dozens that I have worked with that looked like it was created by someone that understood database design.

I really wish this wasn't almost universally true, but after years of sad experience I expect it.