You dont need KT to counter IS2.
Panther can do it very well since it has better range.
You can also combine KT with pak 43. KT+pak can easily counter 2 IS2s.
Not to mention that you will get IS2 around 25min while in 4v4 can hit the field around 15. By the time second IS2 arrives you can get a Panther. Even in 1v1 2 IS2s are facing KT and Panther so I have no idea how did you figure out that OKW can get only 1 KT and nothing more.
In fact you dont need anything more. In 1v1 Ive killed many IS2 with pak 43 doctrine (Ostheer one with railway-artillery).
Uh, we are talking about
multiple IS2's in conjunction with other units
specifically in team games were you have multiple factions.
Panthers aren't a reliable counter to multiple IS2's due to the lack of DPS a Panther can put out if you even assume all the shots from the Panther penetrates.
OFC you also assume with the Pak43 that it's impossible to decrew, which it isn't and you get a tool in the best IS2 doctrine (flame barrage) to deal with it.
KT in any game mode isn't a reliable counter to IS2's simply because they can out produce you, at 380 fuel (tech costs included) your paying a LOT for that KT compared to what he's paying for that IS2, not to mention dealing with the reduced fuel income...
In 1's it's a drastically different story from 4's, and comparing the two in unit usefulness isn't easy.
That's funny. You're funny.
IS2's are counterable with units entirely out of OKW tier 0.
Racketens have enormous pen out of the gate and volks are vet 5 by the time they fire 3 shrecks at an IS2. Racketens also vet up quickly, and are retreatable for easy preservation (and easy re-crewing). Yes, they die easy, but so do all AT guns.
Yes, it's not ideal, and will bleed you MP, but there's absolutely no excuse for losing a KT to nohing but IS2's as long as your infantry is alive. And it should be, because obers obliterate allied infantry in comical fashion.
This is entirely assuming A. you are not using shock troops which rip Volks to shreds B. He's wasting MP on Racktens which means he's an idiot C. That the shreks pen the IS2 (and they won't take 3 pens to hit vet 5) D. The IS2 isn't one shotting squads as it often does (or at least severely damage them) and finally E. That in a team game that your KT isn't being shot at by more than the IS2's and that your only facing 1-2 IS2's when with 3 Soviet players you can easily get 3+.
The puppchen is total unmitigated garbage, works kinda okay with trenchs and buildings, but by the late game it's useless because all the buildings will be dead and the DPS on the field is way to high for it to stick around.