Yes, of course you can form 22 CM from the other cases. Been doing it for the last year... I prefer to start from 6mm brass as there is less sizing to do.
And I will turn my necks before necking down to avoid donuts. 22 CM brass is factory available so the need is dropping but if you have a stash of other CM cases, have at it.
Can work very well. Annealing should also be part of the process.
give me a shout if I can help
Jerry