I'm a bit skeptical of a paper written by a consulting company that specializes in QA services and training. Understanding a codebase well enough to write useful unit tests is very time consuming and difficult. Teaching devs the same requires domain, development and process skills. Other forms of testing (e.g. end-to-end, browser based, and manual) are much easier for an outside organization to apply based on rules in a BRD or user manual. It stands to reason that a company would write a white paper that nudges customers to a methodology that favors them.