ORIGINAL: SMK-at-work
As for "doesn't make sense" well I'm afraid it doesn't - the CP has 100% supply in those hexes, so your description of losing them due to lowsupply doesn't make any sense to me - how can you have low supply in 100% supply hexes?? how can you have 40% supply in any German hexes as the CP? they are all 100% supply.
I'm not questioning your results - but I don't understand what happened, so "it doesn't make sense" is a statement that I don't understand what happened.
Certainly it is possible to be driven from the Alps - the TE can mass more artillery on the plains for the attack than you can for het defence.
Abandoning the first line of Alpine hexes may well be a good strategy if yuo havent' been able to seriously hurt the Italians - TE supply in the alpine hexes is really, really bad - some of them by hte Swiss border have less than 10% which means they lose readiness even if they do nothing!
Which is my point exactly--I had 10% supply in the mountain hexes and had to rotate corps in and out once the readiness had dropped to 5-6. In Trent the supply levels were 35% or so. And as I said, for periods of 2-3 impulses at a time even clear hexes on the Western Front and Metz have supply down around 40%. This doesn't even correlate to loss of food, because Germany was getting a couple food per turn from the North Atlantic until 3-4 turns ago, and now they are down to their base 7 food per turn and the supply is still the same as it was before.
But I know I had Trent taken in one impulses attack even with two corps full strength corps (one German even) with decent readiness and level 3 trenches in the hex. As I recall the mountain hex just southeast of Trent was also taken in one attack and it was similarly defended and entrenched. I had dug in well before the Italians declared war, but couldnt free up enough troops from Russia and the Western front to launch a good offensive before Italy entered the war and got reinforcements from the British and French. I took and still hold the one clear hex between Trieste and Venice, which because it is a clear hex next to Trieste has generally been in good supply and has so far been impossible for the TE to capture.
As for the western front, pretty much the same story. Some of the hexes were taken by repeated attacks that wore out the readiness of my defenders before I could rotate in fresh troops. But at least 3-4 others were taken simply because the supply level in the hexes was down around 30%-40%. I am still using 1.2B5, but as far as I know the most of the early version supply issues had been addressed by then.
So my point remains, and you said it yourself, you can take hexes in this game under the current system. This is a bit ahistorical in itself (a real WW1 TE offensive into a "fully stacked" Alps would have been a bloodbath), so why make it even easier by messing with trench vs. artillery upgrades?