I haven't been keeping up with Salvador's new books, but I have to agree with you there. As a human, Entreri got to that level in few decades and he may be already past the peak of his physical prime, yet he can still kick most drows' collective asses.
However I'm a little upset that Entreri was so obsessive with being the best. Instead of going through that convoluted schemes to force Drizzt to fight one on one, he should have done his job as an assassin and just sniped/poisoned the goodygoody bastard. Things would have been much simpler for him if just did that.