Well, technically it us possible to get a number from a string using the method here:
It’s just rather ugly!
So you could extract the number from the name and store it in a (hidden) read only field, and then use this field in an automation to set the name.
But then you have an editable name field, which similarly opens up an opportunity for human-induced error
One alternative that we didn’t talk about is to use a method to auto-number the minutes based on their creation date order.
Might that work?