The easy fix for the problem of mixing and matching fonts is a font policy: a decision laying out just what fonts you want to use in any projects related to the business. For most businesses, the problem isn't that everyone involved with the process of creating marketing materials wants to pick their own fonts. Instead, it's simply a matter that they don't have any guidance on what they should choose. Having a list of fonts that can be used on projects related to your business can even speed up desktop publishing projects because you don't have to compare fonts, trying to make a decision on which to use.
A font policy can be fairly simple: it doesn't need to be much more than a list of which fonts can be used in the various documents and projects your business produces, with the possible addition of a description on how to use those fonts. If, for instance, you use a specific font in your logo, you can list that font in your font policy. But the odds are good that you don't want anyone to use that font to set an entire business letter in. Instead, you may want to pick a font or two you know that everyone in your business has access to, such as Times New Roman and Helvetica and limit your projects to those fonts.