Never in the past has Evony held its players up to date on game mechanics changes. And if it ever happened, it lacked the detail required to make balanced and sound ingame choices based on the new changes.

I admire your request, but I reckon it will be in vain. The only way to find out drop rates is by testing it yourself.

Generally there are three different drop rate mechanics on different server (groups). Check your server to see which group you belong to and go to the Guide forum and check out the complete medal farming guide, it shows the different droprates for each kind of server.

Good luck!