Goby or Clown? ID please.

[Chin_Lee]

Bought this fella from Apets this morning and owner said it was a fire clown goby. Can't find anything on the internet re: a fire clown goby. Seahorse Fanatic came by and believes its a Cinnamon Clown without the white stripe. But it behaves like a goby - it sits on the sand and propels itself around like a clown goby or mandarin goby. Its orangy-red with a black mark on the back. Any ideas?
Its sitting in my refuge right now because I want to test putting a few different types of acros in there to see if it will eat their polyps. My last brown gobies I had to give away and Props had to dismantle his entire tank to get rid of his brown goby cuz it was mowing down his acro