Yes, IMO coach augmentation should be done on case to case basis(train to train basis), on the basis of past demands/WL charts, taking on view exceptions an seasonal variations... Rake standardization may be good for rail admin as ease of managing things but not for public and purse of rail accounts.
But again it requires analysis and some CDO constraints like lack of parking space, lack of manpower/coaches, TT slacklines needs to be addressed