Just for fun, here's all the players KJ/KT have brought in and (my opinion) of their success (excluding youth players):
Benik Afobe (£2.27m): Success
George Saville (£1.1m): Failure
Tommy Rowe (Free): F
Yannick Sagbo (Loan): F
Rajiv van La Parra (Free): S (yes I know, controversy etc etc)
Danny Graham (Loan): F
Tomasz Kuszczak (Free): S
Kevin McDonald (£792,000): S/S
Michael Jacobs (£308,000): S/F
Sam Ricketts (Free): S
James Henry (Undisclosed): S/S
Scott Golbourne (Undisclosed): S/S
Kortney Hause (Undisclosed): S
Leon Clarke (Undisclosed): F/F
Nouha Dicko (Undisclosed): S/S
Prices from transfermarkt so don't blame me if they're wrong.
So, looking this over by position, we have...
GK: 1 for 1, 100% success rate
DEF: 4 for 4 or 4 for 5 (depending on how you designate Rowe), 100% or 80% success rate
MID: 6 for 9 or 6 for 8 (again depending on Rowe), 66.6% or 75% success rate
FOR: 3 for 7, 42.9% success rate
Again, just for fun and not scientific but a decent enough simple overview.