You can't blame Lambert for the fact that Dunne and Bent have been injured on and off for almost a year, and similarly Vlaar has missed a chunk of games too.
Warnock has been in steady decline for nearly 3 years. Ireland had one good season, playing alongside Robinho, and seems to have gone into semi-retirement when Manchester City awarded him a ridiculous pay rise.
The others he's inherited are, by and large, pony.