Being the Machiavellian type, Sunset should have a stiletto or Assassin's Creed hidden blade or maybe a Renaissance smallsword.
For the sirens,
Sonata: A carved Oar, Musashi-style.
Adagio: Naval officer sabre
Aria: A retiarius trident.
Also, the Cutie Mark Crusaders join the Canterlot High Sensha-Do team.