I was looking at the halfling Paladin to see how you reverse-engineered the halfling, and I'm curious:
In the updated version Corrin's defenses are (and they are calculated):
AC 20 (10 + 8 Armor + 1 Size)
Fort 13 (10 + 2 Con + 1 Class)
Ref 14 (10 + 1 Dex + 2 Race + 1 Class)
Will 14 (10 + 3 Wis + 1 Class)
So, what I'm trying to say is, I'm pretty sure that the +1 to the 3 defenses is a class bonus, not a size bonus, with the exception of AC, which gets the size bonus.
Therefore, your AC is correct, but I propose that your Fort, Ref, & Will are all one too high.
Anyone agree? Disagree?
Fitz