- [*] Capture and hold 3 Victory Points
- [*] Destroy Flak 88 Batteries
- [*] Win with more than 250 Points (reward: Silver Star)
Note: this a strange mission (other than rest) where so-called Victory Points (marked with stars in white circles on map) are more important than ordinary strategic points - you win when you capture all three [*] with your infantry (you can't build OPs on them). Even if in the beginning of a mission (you start it with forces that survived previous battle on this map) Victory Points are yours, Germans will quickly recapture them and you have to take control over them once again. When fight starts you'll see (at the top of a screen) points/numbers representing the proportion of your forces (number in blue box) and enemy (number in red box). These numbers decrease with a loss of Victory Point and with loses sustained during the fight: when you see "zero" - end of fight/mission. If you want your Silver Star you must win with over than 250 of these points on your account. Don't rely on allied units locations you see on my map - they're in places where they finished previous mission.
On an intro to this mission you'll see allied fighter planes strafing german 88mm Flak 36 AA/AT guns battery. 
Unfortunately, it seems that the airforce screwed up the job because in a proper game battery still functions and you receive a secondary task of destroying these guns [*]. Besides the battery of 3-4 Flaks 36 on the north Krauts placed also two guns of this kind individually - I'm not sure if you must also destroy them to complete secondary objective but you can disable them with your infantry squads using the grenades (at least this at the right (east) edge of a map) but you must hurry! Area near the last Flak 36 gun is mined so don't push there any vehicle! 
Even if you are not able to kill the crews of these single placed Flaks 36 with your infantry, you should have a possibility to bombard them with the help of your howitzer, located on the hill 317. Do the same with Flak 36 battery situated on the north - even if your howitzer has not a range there you can fire your rounds very close. It should be good enough because the dispersion of howitzer rounds is pretty big and few salvos should neutralize german battery. 
At the start of a mission you'll see allied reinforcements arriving at the town of Mortain - M10 tank destroyer, an ordinary Sherman with 75mm gun, Sherman Crocodile, halftrack and infantry squad. Try to produce couple engineer teams to follow every tank. Send M10 to the east, in the direction of local Victory Point (capture it with sappers): you can use the road or drive up the hill 317 - this tank destroyer will have a task to wreck every german vehicle (Stugs, armoured cars, Ostwinds, etc.) pushing towards the Victory Point or uphill. 
Move with ordinary Sherman tank and a halftrack (arm this one with MGs) on the hill 317, its western slope (tank can drive the road) to repel furious attacks of big amount of enemy infantry of all kinds (I marked these Krauts on my map symbolically ;-).  As you see Jerry attacks taking same routes as in previous mission.
Remember about the possibility of shelling with your howitzer rounds Germans pushing uphill. 
Crocodile tank (with a flamethrower) can move to the abbey on the west to capture (with engineers help) and protect local Victory Point - as you remember there are some buildings in the abbey so if Germans will try to seize them, your Crocodile and sappers can burn them to the ash. 
If you don't see Germans there you can try to drive with this tank to their base located south-west and start demolishing all around: burn tank factories first.  You can help yourself with second Sherman tank taken from the hill 317.
You will earn some command points during the game - I suggest to spend them on Armor Company, tanks are powerful force. 
Try to capture northmost Victory Point with your Sherman tank supported by engineers.