Optimum Supreme wrote:"It is "Convoy Grand Prime", written in plan English on the box."
A rose by any other name... It's clearly the red/blue Optimus torso bot for Japan, making it the equivalent of what Hasbro called Ultra Prime. What Takara writes on boxes in English doesn't change that, Japanese products use all sorts of English in all sorts of ways, not always particularly consistently.
No, that is not true. Hasbro has clearly stated that the whole point of Ultra prime is that he can combine anywhich way he wants. He's the poster child for the whole combiner Wars line (literally).
And the box art shows it as much, he has no specific limbs for him, nothing colour coded to interact solely with him as the torso.
Grand Convoy Prime however,is ONLY formed with those specific Autobot limbs. So as you can see, different names, different configurations. thsi si not interpretaions, just pure facts given to us by the toymakers themselves through marketting and release material.