Uh, don't worry, I already did that.
Okay, first off, it's not an edit of SonicRE as the whole thing is one pixel BIGGER than Sonic RE. Nothing matches up correctly. The eyes, though similar, are not quite correct, and the hands on SonicRE are bigger than Yoto's. SonicRE's head is big, but Yoto's is smaller, and the ears are VERY diffrent. SonicRE's faces to the front, while Yoto's face the side. The shoes on Yoto are again, ALMOST the same, but still one pixel larger. The legs are larger and curve inwards a little less, and the muzzle on Yoto is higer up than SonicRE's, but the same size (This could be because Yoto and Dr. P both used Sonic as a base).
So, even if he WAS made from SonicRE, there are enough diffrences to make it an rather large edit. But the evedence shows that it could not possibly be made from SonicRE without so much editing that it would be a waste of time to use SonicRE anyways.