So let's add another piece to this puzzle.
Apparently, when the card has a skill that specifies the target of the Cannons, like "Bounty Hunter" or "Corsair", it ACTUALLY means the Nation which those classes are associated with.
Corsair is Bellator
Gypsy is Sanctus
Bounty Hunter is Maquina
The reason I say this is because I've been experimenting with attack teams lately, and came across something interesting. I used an all-Maquina attack team consisting of:
Shore Driven Lael (Bounty Hunter, Maquina)
Skill: Catch a Tartar - Bounty Hunter ATK+ 2 Cannons
Expert Engineer Dharma (Bounty Hunter, Maquina)
Skill: Transom - Bounty Hunter ATK+ 1 Cannon
Cyborg Zola (Bounty Hunter, Maquina)
Skill: Revenge - Bounty Hunter ATK+ 2 Cannons
Andred the Victorious (Corsair, Maquina)
Skill: Rope's End - All ATK+ 1 Cannon
Sniper Cecil (Bounty Hunter, Maquina)
Now, Andred the Victorious is the odd girl out in this formation for being the only Corsair here. But every time I attack someone, one or two of the three "Bounty Hunter"-only skills has latched on to her even though she's a Corsair. I can only attribute that to the fact that she's from the Bounty Hunter nation. Furthering this theory, has anyone had Holystone or some other Gypsy ATK buff work on their Gypsy Faires? I know it hasn't worked for me at all.
Anyone else experience the same? Let's crack this one.
On a side note, these skills are for real. This attack team has a total ATK of 27736, but I have consistently had a final ATK total of 43000+ when all the skills activate (which is easy, considering they're all at the max combo level of 200). I still don't know the math behind it though. ;/