your temp is fine if it fluctuates 5C on average
if it fluctuates 10 C+ then it means one of these reasons if im not mistaken
1- cards are not getting power properly
2- something wrong with overclocking settings
3- card issue needs to be cleaned from inside or need to be fixed
beside that I would like to suggest, if u want to do overclock & fan settings, do it from HiveOS and disable the control fan from claymore, unless u like to write too much commands instead of using GUI
the command (-tt 1) in claymore will disable fan control by claymore
I have an RX480 gigabyte
and this is my settings
hope it’ll be useful fore u