We can know anyone's unit strength by using THE WORLD'S MIGHTIEST ARMIES.
Here's how :
Sum all of your unit's stength and divide them by the percentage that is shown on the newspaper, which would equal to the total unit strength of every unit in the server.

Then, to find a country's unit strength, we multiply the answer that we got from above with a country's percentage. That is how we can know the unit strength of their army.