I remember him sort of saying this in an interview a while back I reckon he would have signed Saunders, Murray and Eubank Jnr, etc if it wasn't for GGG. (same with Kovalev at light heavyweight, though the UK hardly has any good light heavys.)
You say this despite the fact he invested a lot in Bellew when Stevenson and Kovalev were at the weight.
He does have Middleweights though, John Ryder who I know Hearn believes can get to the top. Eubank is tied up with his dad, Saunders is with FW and Murray was fighting for Hearn for a short period of time but he soon left for whatever reason. Hearn did have Barker and still has Macklin so he has actually had 3 of his best fighters of recent years in that division.
And don't forget Adam Etches. Who yes is not technically a Matchroom fighter but is fighting on a prime slot on the Kell Brook undercard on Saturday. I wouldn't be surprised to see Etches feature more often on Sky Sports if successful.
Lets be honest.. Hearn doesn't give a **** about Ryder.. Ryder is good prospect I rate him highly, but Hearn doesn't promote him good, he doesn't promote him the same way he does with the likes of Joshua, Campbell, C Smith,etc.