JagdpanzerIV wrote:yes but to do damage the shell needs to penetrate.
Well, not always. For example the SU/ISU-152 could not really penetrate the armour of Tigers and Panthers:
the massive blast effect from the heavy high-explosive warhead was capable of blowing the turret completely off a Tiger tank. A direct hit usually destroyed or damaged the target's tracks and suspension, immobilizing it. While the low-velocity 152mm shell did not generally penetrate heavy armor, it frequently killed or severely wounded the crew through spalling (splintering) inside the hull as well as injuries caused by blast concussion. Surviving crew were often left with an immobilized vehicle which had to be hurriedly abandoned before being destroyed.(Wiki)
In many cases, when they could not penetrate the armour of a tank with a certain gun, they just aimed at the tracks to immobilise it. Then an immobilised tank is little more than a gun emplacement which can be easily flanked and destroyed from the back. I guess the heavier the shell is, the easier it is to damage the track of a tank with it.
the thing is, for one panther tank there was 10 sherman tanks in normandy, so the game should have been balanced around prestige and numbers of units available, instead of HA, GD values.
Yes, the stock campaigns should have been made very differently, I do not argue that. However, and let me be the devil's advocate for a moment, the AI of PzC has some limited skills i.e. it only attacks if there is a favourable battle outcome prediction. Which means it would never use its numerical superiority to slowly wear down superior units at the cost of losing more of its own.

As a result, I guess, they decided to unhistorically boost some Allied units so that the AI will still use these for attacking.

On the other hand, it was overdone a bit, and you are right that many stats are incorrect in the game and should be fine tuned.
For the hellcat, the fact that it was very fast doesn't mean it should have a high HA value, the fact that it can move 6 hex is already good and also its initiative could be boosted, or the speed reflected in ground defense (harder to hit on the move...etc.)à
That's what I meant when I wrote "endless debates over the values". Some people prefer one way of depicting certain attributes of a unit in this abstract and over simplified system of PzC, others another. So who is to decide, which one is right?
the campaign is doable because we have strong tactical bombers like stukas and such to take out american tanks, but during ww2, destroying tanks with dive bombers or firing rockets at them was largely unsuccesful.
hmm... so you are debating the depiction of tank stats in the game, saying they are unhistorical, but tend to accept and use the unhistorical stats of ground attack planes?
Other than that, I am aware that the general effectiveness of ground attack planes in ww2 directly against tanks is debated, however, there are some contradicting things as well here. For instance, as far as I know German tanks were only permitted to move at night in Normandy due to the Allied air superiority. But, if planes were so ineffective against tanks, why did they have to introduce this restriction? And why did they put great emphasis on providing mobile air defense units (Mobelwagen, Oswind, etc.) to panzer divisions late in the war when the Luftwaffe lost air superiority? Also, on occasion massed air attacks could be devastating against tank concentrations, even if they were largely ineffective against individual tanks spead out in a large area. And there are all those soft skinned supply vehicles (repair, maintanance, recovery and fuel trucks, etc.), which are not depicted in the game (and thus I consider them to be part of each tank unit), but were essential for an armoured division and were highly vulnerable even to machine gun fire. These did suffer from air attacks and the loss of the support column could immoblise the whole tank formation in a very short time. Probably it was a major factor for so many German tanks had to be abandoned and destroyed by their own crews during retreats. And a lost tank is a lost tank, no matter if it was lost directly or undirectly due to an air attack.
Field Marshall Erwin Rommel’s Defense of Normandy During World War II
But it was Allied air power that gave the Germans the greatest headaches. On June 7 Panzer Lehr began its move from Chartres to Normandy in daylight. Its commander, Fritz Bayerlein, who had also seen service in North Africa, objected but was overruled. As soon as the armored column was spotted it was savaged by Allied fighter-bombers. Bayerlein described the roads as being ‘a fighter-bomber race course.’ His division lost 150 trucks and fuel tankers, five tanks and self-propelled guns, as well as a number of halftracks and prime movers in a matter of a few hours.
http://www.historynet.com/field-marshal ... war-ii.htm