Well, it would probably be better for my nation to get rid of it all together, because really, my nations military relies on flight considering I am pretty sure I have both the lowest tech level and lowest population (And the my grand arch-mage that I am going to get from category one is going to more of an ambassador) and trying to wear heavy armor on a pegasus/hippogriff probably won't even let the pegasus get off the ground, and a griffin probably just be a big target. My whole logic of having more heavily armored ground troops is to diversify my army so it isn't just scouts/archers on pegasuses(still wondering if it is pegasi) and spearman on griffins. 

And my logic for having platemail instead of another armor while being rank 1 is that I am rank 1 because basically all scientific progress started with the agricultural revolution, and they are mountainous people. However, being on a mountain, they will probably be pretty good at what they do make, sense there is normally quite a bit of minerals in the mountains. Also, I looked up splint armor and that actually looks more complicated, though I am not armor-smith.

Though, it doesn't really matter, if it is a major issue, I will just remove heavy armor from my military all together.