Rarely were the T-34 Model 1940 equipped with radio. But most, if not all, of Model 1941 were equipped with radio. Those normally being platoon commander vehicles.
The crews weren't trained in tactical moves as the Germans were. From many reports in 1941 the German tank crews describe moving formation of T-34s (line astern) being attacked at the front. The T-34 crews instead of spreading out into a battle line, moved around the destroyed tank and carried on in single file. Obviously making easy prey for the anti-tank artillery or tanks in front.
The Soviet commanders were also to blame. The junior officers especially lacked any conviction in their orders and many countermanded orders were given, which would confuse anyone let alone someone with no tactical training.
An example of German superiority in tactics are easily shown by the actions XLVIII Panzer Corps '42-43. Col. Balck managed to encircle three Russian Armies (2 Tank Armies, 1 Army) with only 2 Panzer Divisions.