All I can say to that one is that if enough water changes and filtration is offered, it's not impossible for shorter term, but 2 bristlenose, if healthy, will outgrow a 10 gallon tank, not just because of waste, but size. If starting with small enough bristlenose, it may not look like a lot now.... 6 months isn't really a "long time" in the life of a fish that lives 20+ years. If healthy, they will grow, in spite of the size of their tank, and I've seen some horribly disfigured fish raised this way. It was very sad to see.
I once had a customer bring in a Jack Dempsey
... it was about 10 inches long and the most brilliant colors. The guy did a 100% water change daily, and fed 3 times/day with some good and nutritious foods. The horrible part about the situation was that the fish, while beautiful, had a spine that was kinked the entire length of the fish. When we put the fish into a 40 breeder quarantine tank, with perfect water chemistry and extra filtration, the fish was not able to hold itself upright or to swim... it just laid on its side in the same spot we had put it when releasing it into the tank. A little over a week later, the fish died. That fish was 2 yrs old... should have lived to be 30 - 40 yrs, at least. The man explained to us that he'd bought it at about 2 inches in length 2 yrs prior, took it home to his 10 gallon tank, and was content with that one fish for 2 yrs... but "got bored with it cuz it didn't do anything", and decided to get rid of it.
I guess what I'm trying to say is that just because we CAN do something doesn't mean we SHOULD do it... and that not everything we do is good for long term situations. My last neon was with me for 10 yrs... so I know these fish have the long lifespan if they're provided for properly.