Find your tribe in a Sea of Creativity
Married on the battlefield and you won't change my mind!!
I did think about Draxum officiating their marriage, but he isn't really much attached to humans traditions. And Donnie isn't as close to Hueso like Leo is (for y'know, pirates of the caribean ref XD).
Tho it maybeh would have been funnier if it was Warren and Hypno, I can imagine them being closer to the couple in the future, especially April; since she is great fan of Warren XDD
And Leo is their Leader, probably the highest authority they have at the moment. They do with what they have XDD