MAP to TIER assignment

Suggestions
1

Somehow I seem to be a bit stupid here, or I can’t find anything in the forum to answer a question I have.

So far I have landed on the following maps with the following animal levels, but I have not yet played all animal levels sufficiently to be able to create a complete picture:

Tier 1: Tunis / Moscow / France
Tier 2: Tunis / Moscow / Stalingrad
Tier 3: Tunis / Moscow / Stalingrad / Normandy
Tier 4: Stalingrad / Normandy / Berlin
Tier 5: Normandy / Berlin

Now my actual question:
Is there somewhere an official assignment of the former campaigns to a preferred tier level for each faction?
So that at the end you can say which animal has the highest probability of landing on a certain map?
Or does the tier stands für the year of the war?

2

US: BR 1-2 Tunisia/Pacific | BR 4 Pacific/Normandy | BR 5 - Normandy only
Germany: BR 1-2 Moscow/Stalingrad/Tunisia | BR 4-5 Stalingrad/Berlin/Normandy
USSR: BR 1-2 Moscow/Stalingrad | BR 4-5 Stalingrad/Berlin
Japan: Pacific in all BR’s
BR 3 has equal chances to see either 1-2 or 4-5, so diverse maps