never heard that adding more lams to a hill - or any bow, for that matter - will make the bow comparatively faster, given that the holding weight is exactly the same. hard to believe. in fact, i'd say that the lighter the limbs, the faster the limb speed.
take two hill bows that are identical in length and holding weight. limb and riser materials are the same, 'cept one has 5 solid tempered bamboo lams and the other 3 solid tempered bamboo lams. each is tillered to 28" perfectly. both shoot the same 10gpp arrow through the chronograph. imho, the 3 lam bow will be fractionally faster due to two less glue lines worth of weight, for lower limb mass weight, and less weight of the same strength is just ... faster in recovery.
i don't know or care what the chrony speed of my 70", 54@29 tembo is, but in comparison to my mohawks and moab, when flying the same arrow at 30 yards she ain't as fast but she's also no slowpoke slacker.