It's finally done. After five days of non-stop testing, finding the right guide, and ModBuddy being a CrappyBuddy; unexpectedly crashing at any given time, and SevenZipSharp errors that made me have to cross my fingers every time I rebuilt my mod for testing, I've completed it. I've triple-checked my code; Every. Single. Line.

Using Kael's modding guide (Which you guys should use if you're ever going to make a mod), and I came across a chapter with ArtDefine, which made me think that the reason my submarine was a spearman, was because I didn't even DEFINE its ART. I think the reason why it was a sub when I had Blaze replace Byzantium is because Byzantium is hardcoded inside the game therefore uses the default art for units, I guess.

The Deep Typhoon was spawning as a spearmen for some reason...

The Deep Typhoon was spawning as a spearmen for some reason... And I accidently uploaded this as the Vanilla version. I shouldn't be editing my mod at 4am. XD

So the reason why I had to separate the mod into two versions is because that the nuclear submarine is a late game unit whose coding was changed dramatically for BnW (combat class, default AI, prerequisite tech, flavors, and unit promotions, etc.) I'm sure many modders already know this but I had to go to into the Civilizaion 5 installation folder and look up the data folders within it to find out that BnW changed coding for units that already existed in Vanilla. While releasing this mod without knowing the differences in BnW and Vanilla is quite embarassing, now I feel bit more comfortable making a Civ 5 mod now that I've familiarized myself with the structure in its code.