First off, thanks for watching it helps a lot.
Extra Pieces:
Austria: 5 - 10 control markers, 2 planes
Russia: 5 or 6 infantry
Germany: 5 - 7 infantry, 2 planes ,5 -10 control markers
France: 2 more of all land units , 2 planes
UK: 3 Transports, 5- 10 control markers
Ottoman Empire: Nothing extra
Italy: 5 Infantry
USA: Nothing extra
These are just rough estimates of what you will need. This list is based on what I need. I suggest that you play it a few times before buying extra pieces to see what you need.(Germany still needs more Infantry and control markers)
You are right about how this game draws so much criticism. When this game first came out, it sold for 100 US Dollars. Now you can get a copy for 60 US Dollars on amazon. There is not a lot of unit originality with this set. The only unit that is different from nation to nation is the infantry. All the other units are the same.
Thanks for watching!
-HJ