Why don't they simply add another record ("source") to help make the driver comparison? A typical Microsoft solution I would say.
Windows already keeps track of the source when ranking drivers, it's just MSFT changed the default Window policy to ignore it (to address certain issues, some technical, some political) and apparently used this kludge to mitigate some of the tradeoffs. The blog description skipped over several steps on how Windows ranks drivers. The first and main criteria is on how a driver is signed (i.e., the source), and only after that does it potentially need to tie-break based on the blog's description of hardware IDs, dates, and file versions.
Lowest rank score wins, and an inbox driver (i.e., a driver included with Windows) is scored 0x0D000003, which is higher than a WHQL signature score of 0x0D000002 or 0x0D000001 (according to setupapi.h in the Windows SDK). However, in Windows 7 the default policy was changed to now treat all signers the same, which now effectively ignores the source. Apparently this date is used to still try to favor vendor drivers despite this change in policy.