I tried the following:
added Humanity to the inheritance list: same effect (even though there are more sizes available) replaced Humanity-Dark with Humanity: same effect.
Made a symbolic link to the Humanity mimes: same effect. Some icons get increased to 200% while others only grow to 150%.
Either the icon themes are broken or it is something we oversee.
I tried the following:
added Humanity to the inheritance list: same effect (even though there are more sizes available)
replaced Humanity-Dark with Humanity: same effect.
Made a symbolic link to the Humanity mimes: same effect.
Some icons get increased to 200% while others only grow to 150%.
Either the icon themes are broken or it is something we oversee.