Obviously nothing as they haven't played a game. I'm basing my opinion on previous seasons. But all the players listed in the OP (probably with the exception of Gallagher) are better strikers than David McGoldrick... That is based on FACTS, goals per game, actual facts!
I have nothing against David McGoldrick and what an astute signing he is proving to be, but the other players would've scored equal to, if not more than the 5 goals DMcG has scored, if they were playing for us.
I'll use Leon Clarke as an example - CWAK somehow got 19 Championship goals from him last season, Leon fucking Clarke!! My point is, they are doing the same with David McGoldrick now who if truth be told hasn't had a very good scoring record for a striker over the years. So, back to my original point in the thread, imagine what they could do with a striker who has scored decent numbers over the years.
Another example - Billy Sharp. Everybody knows Billy scores goals, he has done throughout his career, but, he is currently enjoying his most prolific spell at ANY club throughout his career.
CWAK could probably get Conor Sammon and Michael Higdon scoring goals