New weapons definetely make a difference...
How would the T-34 be addressed without new tanks that could actually defeat it in combat? When the germans first encountered the T-34, the tanks they had at the time COULD NOT defeat it. Thus, german armored thrusts could be stopped, and the russains could (and did) cause major troubles for german armor.
And with the T-34 being mass produced, Russia essentially nullified the power of the german Panzers...
The T-34 is of course only one example, but to say that different weapons do not affect the course of combat ignores battlefield reality.

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Seriously, all today is missing is free cotton candy and the annual Bay State Hooker Parade to make it any better.