Not having tried either, what's that spectrum, i.e., how are they different please? Also, how do they compare to Black Mallory and Red Rapperee?
3 Noggins has a sweet, dark profile that doesn't change much. For me, the taste tends heavily to Cavendish and Virginia, with Orientals in the middle ground adding some spice and wood to the taste, with the Latakia adding only a little leathery note. Overall, kinda like a sweet, toasty porter.
Highland Targe is the reverse. If you have smoked Durbar, imagine that incense like interplay of Latakia and Oriental on top of a fuller, sweeter VA/Cav. The latakia, Orientals and Virginias move forward and back throughout the smoke, and it maintains a brighter spicier flavor.
Black Mallory and Red Rapparee tend to lie further afield. The sugar sweet that 3 Noggins heavily displays and comes in third in Highland Targe is barely there in Black Mallory. Its more of a Latakia forward mixture, with a little sweet, just enough to take the edge off. Red Rapparee is a bag of razor blades, a wonder of an Oriental mixture. Orientals and Red Virginia make up the bulk of the taste with Latakia in the back, and what Cavendish is in it doesn't present itself, even as lightly as in Black Mallory.
And now I've talked about them so much, I think I'm going to go dig on or two of them out for tomorrow.