Your plants are the tipe form Mammillaria deherdtiana ssp. deherdtiana
On the interenet are many pictures with these plans but more are incorect identified.
So on mammillarias.net this picture for exemple:
It say is Mammillaria deherdtiana ssp. deherdtiana but is not is ssp. dodsonii
Why is ssp. dodsonii....?
Radial spine: 20 - 21, the lowest longest, to 20 mm long, needle-like white.
Central spine: 3 - 5 and 10 to 20 mm long with a reddish-brown colour and stronger than the radial, the form is straight or little curving.
The plant look like the plants Wolter photo on the field
And a surprie the same plant on the same site as dodsonii
...you see photo Luc and the description
The tipe form is this:
Sure ar formes and formes here is a plant like yours:
More radials and centrals...ssp. Dodsonii haves 20-21 radial and the centrals are evident and little curving
Here is the real dodsonii:
and sure wolter,s photos are great to see dodsonii
All your plans are the same clone?or from seed?...the second photo is very tricky, not all the seed sourses are good, this plants are flowering in the same period and not all the nurserys have do the corect polinizatian...i have a friend who haves hybrids from a good soarce and y don; t give the name.