GO having a higher win rate isnt a remotely useful stat. Its actually beyond useless.
An easy, possible explanation is that, by chance, more of the top players preferred GO and more of the lower seeded tournament players preferred luftwaffe. They could be the EXACT same power level, but if 1 extra top player prefers GO and, say, 2 extra low seed players prefers luftwaffe, I wouldnt be surprised at even a 30% win rate difference.
And sure, you could then beg the question of why this is the case. Surely if top players prefer GO, then it must be better, right? Not really? Just look at faction picks among the top 8. Each player had their own preferences. For some reason, people seem to assume that the top 8 tournament players are machines built to make optimal decisions with regards to coh2. What actually happens is that these players pick what theyre comfortable with, what smashed them in their last set of scrims, what fits their style, what they have fun playing, whats more reliable as a strategy, what fits their understanding of the game, and yes, what they think is most powerful.
I mean, I dont doubt that GO is stronger than luftwaffe. But "doctrine win rates" is a useless argument that isnt really worth the time it takes to type or read. Really, most arguments that include the term "tournament win rates" are worse than anecdotes since they try to parade as something with actual justification.
On the command panther, i can, in general, agree that if it doesnt perform as well in the AT role as the tiger there is some thinking to be done. That said, its cheaper than the tiger, will come at a lower cp than the tiger (cp lowering confirmed, pending final approval), is more mobile than the tiger, comes with a vet 0 permanent commander aura, has more range than the tiger, and has mark target (which does likely mean it performs better against the is2 than the tiger does). I imagine the tigers performance against the is2 isnt what puts it over the command panther, its just another factor that puts GO over spec ops, considering that the tiger also mauls infantry. 200 fuel to counter the is2 and get some scouting, or 230 fuel to counter the is2 and everything else the opponent likely has.
On the panthers role. Its actually a bit more of a generalist AT vehicle (great absolute performance at short, medium, and long) with its main advantage being that it can actively hunt for vehicles and chase them down to find and secure kills. It does best when it can spring on tanks and TDs that are weaker than it...but the IS2 is not one such vehicle. So when I consider the panther vs is2, and tiger vs is2 matchups, this dorsnt sound particularly alarming. This isnt the panthers ideal matchup or use case.