If I have kids I will name them Yambo, Shazam, and Pajamas. But since those aren't Seahawks related, and you can't have them anyway cuz there MINE, how about:
B: Max, Knox, Alex (Unger, Chuck, Shaun Alexander)
G: Maxine, Knoxetta, Alexis or Alexandra
That way, you're triplets can have a cool group nickname like "The X Factor". My advice is to go with something that sounds good with your last name (although with 3 of them, the alliterative same first letter might get tired) or with a unique enough name that stands alone, like say, Yambo, Shazam, or Pajamas.