Roberto will play football which won't work imo, Carroll whilst nowhere near worth the money spent on him needs a team built around his aerial strength to see any kind of improvement. So either they cut their losses or Roberto adapts to play more width with less of a slow passing game. The players they've signed on the whole tend to have been mid table at best with only really Suarez being the exception potentially Carroll, which coupled with the loss of form of Gerrard due to various factors has cost them dearly. In short Roberto would need imo 3/4 years to build a team capable of challenging the CL spots.