I think that Dalaran footman should have a combination of armored torso and tabard because he should look like an armored soldier above all. Thus, he will have a more unique look and be a full-fledged Dalaran defender, IMO

I mean, if you have only a tunic over his chest and pelvis, he starts looking less tanky and protecting.
For me TC shoulders look nice

Escpecially when you have 3 TC points: the shield (the biggest TC spot), a ponytail and shoulderpads - this is a good ensemble of parts, IMO, because they have clear armor spaces between. If you have a TC torso tabard then you shouldn't add TC shoulderpads to have those clear armor spaces between as well.