I think it is not worded clearly. To me, it sounds like the DB does not include a shield, but a shield is often used. So add a shield in addition to the DB listed.
Most of the humanoid races have the s with DB. Elves, Dwarves, Gnomes, Orcs, etc. all have DB between 20 s and 40 s. For RMSS/FRP you get 3x Qu bonus for DB. I think the listed DB is average for the race of that level. With Qu and a shield, it should be higher.
But (!) shields add +20 to +30 DB vs melee, depending on size..
It would be nice if someone else described how they played it.
For "unaware" DB, I always use the Speed Chart from C&M pg 7. Here it lists the initiative bonus for a creature of that speed. So I take away the DB bonus if they can't use DB. This may still leave the creature with some remaining DB; toughness.