My understanding is a true random tool changer uses a swap method.
You would have to have a Tool change arm to swap tools and then a master log file to keep track of the tool pockets and which tool was in what pocket.
not worth it, unless you have lots of tools and tool holders, and want a rotary delivery system. I think I seen Peter Homann has a rotary carousel on his mill, but I believe it puts back the tool used and indexes to the next needed tool.