And also from my experience, and some friends that compared TomTom and HERE maps in my region, TomTom maps have much more "errors" in speed limits than HERE.
On many "faster" roads that are within city area they show "lower" (general) speed limit for cities, and also in many areas where speed limit is lower (school area, ...) they again show wrong (higher) speed limit.
In another words, many sped limit signs are missing.
That also affects route calculation.

But, for example in first post reason could be information in FSP file, because program is including congestion information (at given time) and from that information red route is faster than other routes (shorter).
You can see that in calculated time.
If you remove FSP file, then calculation is based only on speed limits (which may or may not be correct), and shorter routes routes are calculated as "faster".
Check that by comparing calculated times with and without FSP files.