yes it is. Tell that to a turbo 4 cyl with the power of a V8, or vice versa. You can have no torque, double torque #'s than HP...etc. Hell with the amount of different turbos one can use, you cant really say that.

Correct me if I'm wrong, but in a twin turbo setup each turbo is flowing half the psi of the whole (ie. 20psi on a TT car would be 10 psi each turbo) and thus you can go higher, using two smaller turbos that flow better/spool faster, whatever. Assuming you have the power/displacement to do so.