[Taqwus]

The sirens do face a slight risk -- if the targeted commander is lured, but is immune to drowning; then they fight, and while a Siren has magic, it has very few slots for toys. The luring also seems easily resisted. All in all, I'm not sure it's much faster than expansion using Star Children, who can also operate in non-coastal provinces (although Triton commanders are probably still death for them, and they have trouble with the sheer speed of Knight commanders).

It's an interesting nation; the recruitable national tritons are handy. That the Capricorns lose half their magic on land, and that the only priestly unit is aquatic, gives quite a bit of flavor. The latter bit worries me a bit for an AI, 'tho; will it actively pursue getting an amphibious or land-only priest (e.g. by prophetizing, or by summoning?)?