I still want to do a few more side by side comparisons, but off top:
The topping is identical, but stronger in Cognac Mixture. In Pembroke, the latakia and orientals are more present and easier to discern. I can easily pick out some Basma and maybe Yenidje... lots of incense-y balkan flavor with the cognac topping in balance. Cognac Mixture seems to have more Jersey Cavendish and, consequentially, less orientals and lat. Even though my tin is dated 4/18 it seems like it has much more age on it. The black Virginias are covered in the sugarstuff and all the flavors are more melded. It tastes equally of sweet VAs, orientals, lat, and Cognac topping is up front from start to finish where Pembroke's focus continually shifts from one taste to another with the topping in the background. Really very similar. Barely a noticeable difference unless you really concentrate. I'd take either one without complaint and I'll be buying whichever is cheapest and most available to cellar as I could see either being in regular rotation.