Objective 9 : Regroup with Captain Foley and get in the car

After you grab the Panzerfaust, switch back to your Carbine. You'll likely face two more waves of German soldiers, especially on Veteran. One might jump over the wall to the left of the church exit, and another will come from the direction of the distant tank. The ones coming over the wall are the main threat; they can sneak up on your squad, but they usually come in a single file, making them easier to deal with. After that, take out any remaining shooters in front of the defenses before you focus on the tank.

To avoid getting left behind during the tank attack and dealing with what seems like a permanent respawn of soldiers (again, possibly Veteran-only) coming over the wall, you need to be quick. As soon as the mortar fire starts, sprint from where you picked up health towards the overhang and then into the alley without stopping. While you're running, switch from your gun to a grenade and toss one into the alley. This is way better than waiting for the soldiers to show up and risking taking damage.

Don't risk going behind the tank, as you'll be exposed to those respawning soldiers. It's much safer to clear out the area around the tank first. Wait until the gunner on the tank stops firing, then make a break for the church. This route is a lot less dangerous.