Well, to begin with they are two separate yokes but the are designed to act as if it was one.
They do not teeter and flap and hunt as individual yokes, they do not teeter at all since the rotation plan is the same as the oke mounting plan.
It's pretty much a single rotor head with staggered blade couples. the Bell 430 rotor head, derived from the 680 type rotor has the same characteristic (staggered yokes), however the yokes' arms are much longer and these are made of tightly wound composite materials rather than metal.
The main difference is that the pitch change links work on the blade in the 412 rather than the yoke in the 430.
I learnt not to criticize something I know nothing about, I may end up with the classic foot in mouth situation.