Ok so I attacked the battle area on the top left with Staudt Schumacher and Jantzen, but in the tactical battle I only get Staudt and Jantzen platoons (why not Schumacher?), but I also get the AT gun platoon even though I didn't attack with that unit.
On the other hand, if I initiate the battle in the middle (which was a counterattack by the enemy), I get Jantzen, Filian, and Krautz AND the AT gun.
So basically my question is why does Schumacher's platoon not appear in the top right battle and why does Filian participate in the middle battle but Arndt does not?
What rules govern whether a platoon is in the battle or not?
Also, how do I get 4 units in one grid area? At the beginning of Operation Star there are 4 German units in one grid (3 infantry platoon and 1 supply depot) that are surrounded, but normally I see grids only allow 2.