Yes, I find it surprising (and sad) that Yamaha can't get consistency between the SA and Mega-voice voices between the arranger lines and Motif. This goes back to the very first Mega voices and SA voices. For some insane reason, Yamaha's left hand ignores what the right is doing (or copies it badly).
What is not surprising, is how well both divisions are doing with their respective products.
Obviously, it's working regardless of any inconsistencies, real or imagined.
Some companies have had to stop making arrangers because of internal inconsistencies...
Ian