I've got a questions to more experienced HOI players. What happens when the nation you play get annexed? Can you still continue to play as the same nation and somehow try to regain your independence (I'm thinking playing as Poland)?
Im pretty sure that even someone who is totally new to the HOI series shouldnt have problems to survive as poland in the 1936 scenario in Hearts of Iron IV.
Daniel showed us that as a fact, when he played Hungary in the WWW.
Even when he played Poland in the 1939 he had quite a good chance, if you start in 1936, it should be possible to win vs Germany AI with Poland.
In HOI II + III it was so, that if lets say you play Poland and are in the Comintern, you could draw all your armys to moscow, but in the moment that Germany got all your Victory Points, you will capitulate ( automatically ), the game is over for you and all your troops will vanish ( yep, also the troops in moscow ).
That was pretty much an unrealistic system.
Though the AI could play further on in HOI III as exile government, but so I remember, the player couldnt.
If you are totally new to HOI IV and you want to play with Poland, it might be wise to play the 1936 scenario and maybe try to get the focus tree all down to join the Comintern, with the Soviets on your side and 3 years to build up your army, you should make impreza (Party) at the latest of 1941 in Berlin.