First mission (left flank): Move all your forces to the far lower left corner of the map and then run up the hill on the far left edge of the map. It is easy to flank the Pak and German infantry there. Then run across the German line from left to right until you’ve killed all the units on that front line. Reinforce your squads, using the halftrack.
If you’re using Rangers on this mission, and intend to use them for the final assault, you should now bring in another 4-5 Ranger squads. You will need them immediately at the start of the final assault.
Meanwhile, use the passing US planes to spot for your artillery/CAS, and de-crew the three artillery pieces at the fuel point to the north. Don’t hit the guns directly—try for a shot that kills the crew but spares the gun, so you can use it later. Not essential, but nice to have.
If you prefer, you can rush that point with your squads, but you will take a lot of casualties from the Puma, HMGs, fallschirmjaegers, Paks, and other German units there. Artillery should do most of the work for you on all four of these Siegfried Line missions.
Second mission (middle/road): Take the AT gun and move it up 20 meters or so, until it’s just in range of the Panzer IV across the field. Leave it to kill that tank. The rest of your force sweeps left to take the first territory point with help from an artillery salvo, and then (again with artillery) the point just ahead of that across the ditch. Grab AT guns and HMGs and other weapons there. Use your tanks on the lower side of the barriers for support. Now use passing US planes and your artillery to finish the job if needed by killing the Luchs and other infantry guarding the road point. Alternatively you can use your own units but they will take casualties.
Third mission (AA emplacements): Use the US aircraft overhead to spot the two German AA emplacements, one on the right and one on the left of the German position. When you spot each one, pause and call in artillery on that position. If you’re impatient—the planes sometimes take a long time to fly the route over the left emplacement—you can send a tank down to that left emplacement to spot for artillery: the first salvo can take out the guarding AT gun, the next one the AA emplacement.
Final mission: I prefer to use Rangers or Mechanized. Rangers are easiest. They start by running to the fuel point where they de-crewed the artillery pieces before, and switching on their schrecks to deal with the giant German tank attack that will quickly develop from the east (see image). After that, use captured artillery to wipe everything in range to the east, and use passing planes and artillery to wipe German units by the bunkers at the hilltop, the priority units being mortars and fallschirmjaegers (and take a few shots each at the bunkers). When you’ve thinned out that infantry and there are no more mortar teams, and you’ve been given a Sherman and a Wolverine, send your whole force, with the tanks, to the hilltop. The tanks can focus on the two bunkers and the Rangers can focus on German infantry. Should be over in a matter of seconds once the tanks are there and firing point-blank at the bunkers. Mission and campaign accomplished.
If you have been doing the campaign without Fox, you might find that while some of the missions are tougher, your final score is much higher.