Special units are usually more versatile than normal units like a dragon shaman being able to act as a mage and healer.

I wouldn't bother raising Laurier since I don't find her useful in the long run imo. I would focus on getting the basic silvers from Katie's tutorial maps and story maps and build your core team from there. Now that they took out Cloris' emergency mission tutorial, you need to get a valkyrie (Mischa preferably) and another witch (dupe Calliope or Nenya) from story maps.