Success in this battle means you get a SE Me-109G! When you get the abbey trucks to their exit hexes, that is. The SE fighter arrives during the game and you can use it!
Success here depends a lot on how well you did in the last battle the one where you get minefields to deploy. The more the better--gives you time to deploy and mature your defenses.
As in all battles adequate air superiority is key to reduce losses that urn prestige.
Start off with an experienced 88 AA on the abbey hills next to truck. Deploy your best fighter there.
Divide forces into three balanced combat teams. The first to race to Atina--three units--one for the city, rough hex and airfield (armor on airfield--you'll need this airfield for refueling!, infantry in adjacent rough hex and artillery in Atina city hex, to back them up). The second to attack San Giorgio and Gaeta, the third to race to Cassino. Pull back the Gerbirgjagers towards the hills where you can race in infantry and artillery support under fighter cover. Attack with armor into the river junction across from San Giorgio where a good defensive position behind the river (hex 17,19) will clog and delay Allied attacks. One good unit here can destroy many Allied units trying to breach the river. Move the abbey trucks a square or two at a time with fighter cover and AA protecting until they make it around the bend so to speak. Then run them to their exits. Move the AA back towards Cassino.
You should capture Sperlonga first then Pontecorvo then San Giogio then Gaeta. After this link up with forces south of Cassino at the river junction.Once the river junction at SanGiorgio is sealed slowly advance back into Cassino with infantry strongly backed by artillery.
REMEMBER there is a lot of rough terrain here. *****Keep armor on clear or countryside hexes ONLY and infantry on rough, forest or city*****.
Look at the enemy entrenchment factor!!! Shell or bomb until factor two or less...THEN the main attack.
Beat back enemy air with your fighters. A good tac bomber weakens or kills Allied artillery.
A basic combat team is infantry on city, rough or forest with artillery behind, and armor on adjacent clear hex with a fighter covering all three units. Capture San Giorgio and Gaeta.
Beware the area between Atnia and northern Cassino and the valley to Cervaro--there may be some unexpected enemy units here--USE RECON well so you know what is there.
Tigers help a lot at the key river junction hex. Wuhframen are great at allowing you to advance yet be ready to deflect an enemy counterattack on the very next enemy turn! A towed artillery unit with three hex range is good to--maybe one. Buy that artillery!
After exhausting*** enemy attacks move on carefully to Cervaro and Castelforte for decisive win. DON'T overreach to the distant cities and airfields--your mission is to exit the tricks and gain major victory hexes. You may lose a lot of prestige trying to clean up on outlier objectives that don't reward you.
Recon Cervaro and Castelforte well before attacking. Prepare attacks there well.