could be worse, they could have been hyped up as the greatest fighting force ever and then turned out to be pretty useless...
I assume villa4europe is referring to the Unsullied?
I can't remember if the point has been made on the show or not but the Unsullied are the best soldiers in the world - in an open pitched battle I think the idea is they'd stomp everyone. What they are not though is urban policeman. 8ft spears don't help much during fights in alleyways which is how the Sons of Harpy operate.
This is another detail the show has had to (rightly) gloss over from the books