Also, I think that Poland will have taken measures to watch the Reich, given that the Reich laid claim to their lands. I wouldn't be surprised if they had eyes all over the border and scoured it daily for the possibility of a Reich invasion.

They may be behind, but none of these countries that you have laid claim too are going to be unprepared, they are going to have been training their soldiers for this day and making plans, digging out their defenses etc.