Didn't you read my explanation on the first page? On the wiki we credit toys to all of their designers if known. Toy designs are a collaborative process between the companies and design teams, so nobody gets all of the credit. I mean, I linked Alex Kabalsky's wiki article which lists all of his currently known designs, some of which are also credited to Hasbro's designers.
Unfortunately, it's much harder to get information on Takara's design team and who designed what toys.