Since you can only apply for your MOC's NOM based on your (or your parents) legal residence, best to assume they are ALL competitive. Not likely your family is going to relocate to someplace 'less' competitive.
It definitely could be an asset and could help you. It's unique especially when they ask why do you want to go to a service academy. I wouldn't get too worked up on being from a competitive district. More numbers doesn't always equal more quality. And my congressman manipulated the numbers as best he could to nominate as many individuals(lamborn CO-5)not all do this either though. I remember thinking about the same thing as far as competitivenes but was surprised to hear I got a nomination! I actually got one from my senator as well (cory gardner) but he took it back when he learned I already had a Nom because they don't double nominate apparently. (which also works in your favor because if you don't get one from your congressman, the kids that did won't get another from the senator leaving you in the mix). Not everyone wants to go to the same school as you as well and I definitely think my wanting to go to USMA helped me a tad since A LOT had AFA as their first choice. the AFA Nom rejections were given their other options like USNA USCGA and USMMA because those were less desired and for some reason harder to fill. You can't control who applies and why and the process but you can control your interview and your application. Just my thoughts