the 'traditional' way I reckoned on two days per page for the 'realistic 'stuff. These take a fortnight or so per page but then I am not at my desk from 9 - 7 every day. Am getting more 'painterly' and less meticulous with this software with the intention of speeding up. Which I will need to do if my ambitions for a cast of thousands are to come to anything.
Later: should add that back then there was a clear aim in view and I was disciplined, organised and methodical. None of those things now.