There's also the multiple repository tool 'mr' http://linux.die.net/man/1/mr http://linux.die.net/man/1/mr which adresses exactly the I don't want to waste time

There's also the multiple repository tool 'mr' http://linux.die.net/man/1/mr http://linux.die.net/man/1/mr which adresses exactly the I don't want to waste time dealing with multiple commands to manage multiple repositories complaint of the author and moreover can do so for repositories using different version control systems. I've been using it for years mainly because I have a few repos shared between projects and jobs, and using one monolithic repo would mean having to copy those repos around. (At least AFAIK - or how else do people using one big repository use external projects?)