Equip sets

Just had a question for the Devs(or maybe a knowledgeable player) about Equip set bonuses such as the ones from the Grand Company.

In order to gain some of those set bonuses, you need several pieces of the GC gear, which isn't always optimal gear for a class or job.

I'm struggling to activate my Serpent Sergent's Tabard and Choker while playing LNC/DRG.
They both need 3 items to activate and I don't see a 3rd beneficial item for Lnc/Drg...

Would the Serpent Sergent's Spear activate the set?

Serp. Tabard + Choker + Spear = 3 piece, it would be enough to activate.

If you're wrong sir, my waste of seals shall haunt you all the way from Balmung!