One: You can't compare the Pershing with the Panther if they share similar stats. Panther is geared towards fighting tanks and always has been: it's almost(if not for the MGs) a dedicated tank hunter. Look at its stats: Low/no AOE, good range, high penetration, slow RoF, good armour and speed. The Panther is meant to engage other tanks. Even with the MG upgrades its still mediocre unless you can face all 3 MGs at the target.
The Pershing, looking at the stats, is more of a generalist. Its got a decent reload, looks to have good AOE (not sure on the AOE profile) compared to the Panther which has almost none, good penetration to deal with armour, good speed for a 'heavy' and I'm assuming it has good range (50) (wasn't there to watch and stats don't include the range. Furthermore it fits the USF of being somewhat fragile, but versatile, quick and generally hitting hard.
As for assaulting fortified position, sorry, but few if any tanks can assault a position with 2-3 ATGs in the area. You've got an army to support the Pershing and even smoke to protect the advance or retreat, use it. Even if they bumped the armour up slightly, it's still not going to protect the tank in a head-on assault against dedicated AT as the job of ATGs, TDs, etc are to engage tanks. Furthermore, this tank seems to be pretty good for nuking weapon crews/paks if the scatter is decent thanks to the AOE.
about the panther being bad at AI
https://www.youtube.com/watch?v=zhV6pSzsF6M
https://www.youtube.com/watch?v=xDmeVhgKp7o
if that thing can stand ZIS-3 shots and decrew 6 pounder AT guns with only the frontal MGs then you cant call it bad at AI
also the panther reloads 1 second slower then the pershing (5.5 vs6.1-6.4)
i find it stupid that i have to pay 600mp and 230fuel to get LITERLY a panther LIMITED to 1!
yea sure the pershing main gun can handle infantry better then the panthers BUT the panther has better armor AND mg 42 upgrade for even better AI
i find it stupid that what the USF got is a "heavy tank" that flanks,also its 300 armor and 800hp is laughable