In my 65g I put like about 9 turbos, a few hermits and a few other types of snails. The turbos get to places just fine. Whatever they don't get the tang and the angel takes care of. If your afraid of them starving, some algae sheets would do the trick.
They started wondering about on the second day we got them. Then they started eyeing at the chromises on the 3rd day. They were waiting for them to get closer as they started sneaking towards them. The chromises started grouping together tightly and started going up higher away from them. Then they lost interest and swim away.