Nobody has asked for an I-win button. That interpretation of their words is yours alone.
"Guess what, if you see an American player investing heavily in AT defenses (aka Jacksons) then maybe, and this is gonna sound crazy, you should not invest heavily in a single breakthrough tank"
So what should they invest in? You say Panther + stuka but the stuka vs blob is hit and miss and the Amis will have a blob guaranteed. panther won't stop it and will also have a hard time vs Jacksons.
Well, if the enemy is building a lot of AT guns and AT tanks, you could build more infantry or arty, why would you build a panther to counter AT defense? Then he might build stuff to counter than, and then you counter his counter, and so forth.