I believe they, at least one or two of them were slated to go around the lagoon near Magic Kingdom. Near the Poly, and Contemp. These ideas were pre-Grand Floridian I'm sure.
I just came across a commemorative book pulblished in 1971 that includes a map showing the proposed hotels. It shows the proposed Persian on Bay lake roughly behind the speedway, adjacent to the monorail barn. The Venetian was to be on the Seven Seas lagoon side of the peninsula between the TTC and the isthmus. The Asian was roughly where the GF is today.