Sunderland have left fans frustrated with their lack of activity in the transfer window so far. Sunderland headed into the transfer window in dire need of some signings. Nazariy Rusyn has proven to be the only one of four strikers to have scored a goal this season, while all three of the Black Cats’ left-backs had found themselves sidelined. Michael Beale‘s tenure has gotten off to a rotten start and is in danger of getting even worse if he can’t bring in some players to bolster the club’s promotion hopes. Things are only made more concerning by the transfer activity that teams around them are…