This post is focused on providing a direct link for precious informations about the game engine in a practical and organized manner, so that players and designers can use it as a consultation tool.
I'll be adding links every time I come across something interesting.
Notice that this is not about tactics or subjective interpretation of the system. Only posts with brief and clear information will be available (perhaps with some exceptions, depending on the value of the information).
I'll try to organize it by topics and to specify the patch (the one in use by the time or the one that implemented the described characteristics) where relevant and possible, since this can become confusing when information becomes outdated.
An interesting thread about the attrition divider (be sure to check the second page too)
UNIT ORDERS and ACTIONS
A recent post on gamesquad about disembarking on ports vs disembarking anywhere in the coast
Formulas for supplied units and some supply distribution explanations before patch 3.4.
Meaning of the Defensive Strength Number not presented on the manual.
INSTRUCTIONAL AARs (AARs that can help players understand the game engine)
Excellent AAR describing the first turn of France 1944 D-Day scenario in a very detailed way.