I'm one of those people who actually feel neons are fine in a 10g. This really is a personal issue IMO
. I've kept them off and on for over 30 years and find they aren't really that active (in my tanks). I've also kept Threadfin rainbows which really are very active swimmers and wouldn't keep them in a 10g. I actually have them now in my 220g and they are constant swimmers. So IMO
that stocking would be fine.