I've used the earlyphotography site quite a bit to identify cameras but on this occasion he's got it wrong. The Unit shutter was available at the same time as the shutters in the Ruby Reflex and in fact was improved with the introduction of "The Thornton-Pickard New 1910 Patent Unit Focal Plane Camera Sets".
Many of their cameras could be supplied with this new Unit shuttter fitted including the Royal Ruby, Special Ruby etc but these weren't Relex cameras. The older Unit shutters had adjustable tension, like the T&I and used the same ratchet shutter speed indicator (as my Avatar), so needed two adjustments one to wind and re-tension the shutter, the other to adjust the tension to change the spped. The 1910 Unit shutter is similar to our Ruby Relex cameras, one winding key, they still used the key in 1921 but by 1924 it was a radio style knob.
So in 1910 there's also the new Ruby Reflex with the newer "Unit shutter".
The camera still looks the same in a 1921 advert. So I guess what the site owner calls the Ruby shutter is just in fact the newer type of Unit shutter.