Ok so the way I understand it, the units from a activated unit never stop coming through out the game. Only thing that limits them is how many enter the board at one time, unless all are on the board.
So if if 3 squads are taken out on a turn, and say the rest of that Regiments squads are in play the next turn 3 more can come back?
All above is true if one or more German Regiments have been activated.
German units that are killed remain off the board on their KIA side until the end of the next German placement phase. Then they are turned over and will be available for placement on the turn following. So, in effect, they lose 1 turn when they are killed.