It would really be pushing it, but that probably is possible - provided you're religious about maintenance, have a battery backup for your filter, and have a very well matured tank. Swap the rummy nose for more neons or white clouds and I'd be more comfortable with it.
That's really what thinkfish's calculator is assuming - effectively flawless care. You probably could push stocking to or near the levels they calculate, but the fact that the best among us are still human makes it generally inadvisable.