The T34 is less durable and much less survivable individually than the equivalent alled or axis medium (no escape mechanisms 20 less armor)... but is significantly cheaper and spammable...
For every 4 P4s, you can have 5 T34.
Not sure if I'd call that "spammable".
Also, what do soviets have to do with .50 cal? Oh yeah, the "crutch" thing.