I would put at least one pin through each of the pieces of material. The dovetails should be set so that the less likely to crack is holding down the more likely to crack. However, there is still the possibility of lateral forces. Epoxy is worst at lateral force and the dovetails will hold perpendicular to the tang. So, you need at least one pin in everything to provide lateral security. After all, that is what the pins are really for when there is adhesive used, also. The primary function of the pins is to prevent a sharp shearing force from popping the material off. Secondarily, they reinforce the adhesive by holding things down.
Sure, people always say, "the only reason I use epoxy is to seal from moisture." I do that also. But, the epoxy doesn't know that it is only supposed to work as a water sealant, and so it does its usual job of holding things together against forces pulling them directly apart. It does this well, too. Because of this, pins don't have to resist much force in that direction (or dovetails), despite the fact that they are also both very good are resisting those forces. A shear force, however, that is something that only the pins can really resist.
the dagger is looking good!
take care,
Kevin