Lets say Germany mangages to connect the dots and figure out Russia has the T34 and has the capability of generating these huge reserves as actually happened OTL. (perhaps a high level diplomat or general defects fearing being purged, or Germany and Russia agree to an exchange of officers for cross training, etc.). Lets say they figure this out at the beginning of March 41.
a) Do the Germans just invade anyway (what other good choices do they have at this point)????
b) Can they do anything to prepare better in such a short period of time (increase their railway repair/convert capability????, increase spare parts availability etc.)
c) How would they deal with the T34 if they new about it earlier (a crash program of 75mm anti-tanks guns or a Hetzer like tank destroyer crash program)
I am thinking knowing this the Germans might have been better prepared by the time Typhoon rolls around in October, probably accelerating the long barreled Panzer III and larger anti-tank guns earlier, a bit better logistics perhaps if railways were converted quicker, more spares would have been available to flesh out existing panzer units instead of saving them for new divisions.
Likely Hitler assumes from the get go larger follow up operations will occur in the east in 1942 and doesn't switch production to aircraft and submarines in anticipation of dealing with the west but keeps production focused on east front needs.