Karam,I don't think I can help, it could well all be subjective. Latakia never gave me any barnyard or hay smell or taste, while leather has always been there too (for me).
Gaslight and Squadron Leader are very different though, to the point that for me there's no point in putting them in the same sentence. Gaslight I didn't like at all, it was creosote and tar, while Squadron Leader was nice but quite light for my tastes. In general I have never been impressed with Gawith's use of Latakia.
To distinguish the smoky/woody characters between eg Latakia and Dark Fired Kentucky I'd say the first smells/tastes like a campfire that's died down, while the second like wood chopped and/or burning.
Sweet hay/grass/tea even are tastes I'd experience from light VAs. Manure and cattle piss I'd say is what I get from C&D's Perique bombs.
Thanks for fleshing out more your sensations.
I got the barnstall flavor from about 1/3 of Latakia blends, especially Sutliff's Latakia, Star of the East, Wellauer's English blend, and two English house blends from a local B and M. Those two house blends were the first English blends I ever had, and the barnstall hay smell made me wonder if it was rotten and why people would like Englishes considering the smell.
When tobacco and hay break down in fermentation, they both produce a substance called "silage," and this may be part of the reason that those Latakia blends have a barnstall flavor for me. That barnstall variety of Latakia feels more fermented to me than plain VA tobacco, although I don't know if that's really the case.
When Latakia is very light in a blend like Walnut MATCH, it contributes a faint taste like a campfire that died down. Or perhaps it also has that campfire ember flavor as an aspect in stronger Lat. blends.
Another possible factor is that my palatte may be more sensitive and different than other people's. For instance, Northwoods' smoke smells bitter and soapy in part to me, but other people who smoked it in front of me only got rich flowery, chocolate notes from it, which is what I get from Northwoods' tin note. However, I know that the barnstall variety of Latakia smells stinky to some other smokers, so I'm not alone in it.