There are lots of copies of clash of clans. However this one seems a bit more different then most.
You get a hero right in the beginning and there way more variants of the heroes then clash of clans which only has two.
However it feels slightly overpowered.and the abundance of the gem equivalent in the beginning makes you feel rich.
Maybe they are trying to hook you and lure you in with the op feeling. The single player campaign is pretty easy. And most of the buildings and everything are pretty similar to clash of clans.
So its a copy but a better quality the others i would think.