They definitely all look like mammillarias. Some of these are very difficult to identify at a young age so you may have to wait for a few years to know for sure what they are.
However, the bottom one is undeniably Mammillaria fragilis.
Second last maybe mammillaria marksiana. Couldn't be sure until it goes to flower.
First one might be a young mammillaria hahniana. Once this one ages you will know for sure. M. Hahniana is easily identifiable as it has quite a unique look to it.