There is a lot wrong with your post.
1) Cons are still 240 mp and wait... grens are still 240 mp They did not become cheaper. I played some games and honestly they didn't feel much different except for when they reached vet 3.
2) The Firefly was adjusted and made more inaccurate (or in the terminology you like to use: nerfed)
3) The Firefly's moving accuracy was reduced (nerfed)
4) The Firefly's tulips stun was decrease in its effectiveness (nerfed)
5) The Firefly had its vet 3 bonus damage halved (again nerfed)
6) The Panther had a cost decrease (buff)
7) The Panther had a reload decrease (buff)
8) The Panther had a accuracy decrease for when it's on the move. Only the OKW version. (nerf)
9) The Panther lost the 10% additional armour bonus at vet2 (nerf, then again it has stock an already higher armour value than a tiger and the highest health pool of any non doc tank at 800 hp (it also still gains an additional 200 (or so) hp at vet 2))
10) The Jackson had a moving accuracy decrease (nerf)
11) The Jackson had a cost increase (nerf)
12) The Jackson had a health buff to the level of any other medium tank in the game (buff)
13) The Elefant and JT do not equal all AT. In 2v2 I rarely ever call in a Elefant and I rarely see it called in either because Ost has never lacked for excellent AT.
In summation: Cons are not cheaper, they are not insane, allied tank destroyers received 6 nerfs and 1 buff. The panther seems good to me. The only axis AT that saw a clear nerf were the Elefant and JT, then again being able to 2 shot any medium tank is fun if you got the Elefant but if you face it, it's extremely frustrating on certain maps.
Play the mod. It's actually rather good.
isnt a 6model squad with a 240 pricetag cheaper than a 4model squad which cost 240 to?
240/6 = 40mp / Model
240/4 = 60Mp/ model
and a refresh per model is cheaper too