Mammillaria hahniana

Hello
Is it Mammillaria hahniana or somemthing else? Both plants were bought in 1 pot.

Most certainly m. hahniana. I once had three quite large specimens growing together in one pot, that appeared to be m.hahniana that I bought a few years back now. After separating them and growing on, two were definitely m. hahniana, but the third turned out to be m. geminispina sub. leucocentra. So you don't always know.