That's a mistake on my part, the AP tiers are actually different on paper, but I guess I forgot to reflect this when I was putting it up here. Basically, I just up'd everything by 1.
The second question I'm still wrestling with. On one hand I'm contemplating carrying over the armour ranks, on the other hand I'm contemplating keeping both ranks of armour but the new one starts at E for ~versatility~, and on the other other hand I'm contemplating just restarting the new rank back to E.