Map units

How do we identify the above prior to joining a game?

Start a game.
As soon as you are in the screen where you can select your home country (turn 0), you can take your time and open up "Units" in the top right menu.
Then you can still select a country or leave the game, if you just want to see what units a map has to offer.

Enter a running game.
Spectate, then click on "Units".

Both times you don't actually join the game and can simply leave again.

Apologies for ver late responce.
Thanks Z.