Frostscythe is kinda bad as a talent, though.
In my experience, you get better yields from OB>rime proc than 2 frostscythes. Especially if KM is up. Howling blast (esp with freezing fog) and a maxed artifact (moreso if you get the sigils with +HB damage) will do retarded damage.
I'd argue that HB is overtuned.