We can't us scoring records as a measure of a good striker. Football is not like baseball or cricket, its a team game.
I bet his scoring record (games to goals) is no worse than our very own Darren Bent's, and you wouldn't call him a poor striker. If a good striker plays for a team that doesn't create many chances per game, the goals to games ratio will be low.
You can only assume Lambert has seen the way he has taken his chances and he looks good. His overall play may be good too, like Kevin Davies'.
You can only call a striker poor if he continually fluffs the chances he gets. Lets see what he's about.