All last season Tevez played as lone striker. This argument is a bit sh*t but no striker has a better workrate than Tevez although all his workrate goes towards is the attack. Closing down defenders and keepers and going for loose balls.
You are quite correct, last season until they got Dzeko, Tevez functioned as City's lone and pretty much only attacking front (Kun and Balotelli also weighed in).
That was abandoned (on occassion) towards the end and he has only played in a 2 man attack this season (even if it is limited)
His work rate is like a bulldog.
The basis of the argument is that RvP has a poor work rate, which is nonsense. Because the argument shouldnt have anything to do with a comparison, he either has a good work rate or he doesnt.