It's fair to count that for a QB period; strip-sacks often make pocket QBs their teams leading fumbler, yet their PASSER Rating doesn't even include the lost sack yardage. And, whether many or few, rushing yards, TDs and turnovers all count on the field, so should count elsewhere also.
These things, btw, only make Aaron Rodgers that much MORE amazing, because he runs a lot yet STILL rarely fumbles. Many people have tweaked the PRS over the years by the simple expedient of including runs and sacks as attempts (but only positive runs as completions) and rushing TD and turnovers with passing ones; I bet Rodgers is at or near the top of those rankings. If I weren't so sick and planning a transatlantic move I'd go find out for sure.
None of which changes Manziels need to realize that now that he's in the NFL and compiling a rapidly growing rap sheet he can't spend every night at the Chicken as if he were still in College Station. College Station's a typical rural big college small town whose population quadruples during classes, but Manziels days of being a big fish in a small pond ended when he chose to leave that behind for the big time (which somehow equates to Cleveland thanks to the draft.) No one there's got any patience for the latest Browns QB disaster.