Just some pure speculation here - we all know every spec list from SEGA and even the boxes themselves claim the 32X had hardware scaling and rotation of SPRITES. The speculation is, maybe the original design for the 32X had one SH2 and VDP1 from the Saturn. Such a design would have been almost the same price as what they went with in the end, and WOULD have been a SERIOUS threat to the Saturn market. So the VDP1 was pulled from the design and replaced with a second SH2. The VDPs in the Saturn use a 16-bit bus, so having VDP1 in the 32X would be easy to do. VDP1 reads commands and data from local ram, and stores to two separate frame buffers; the 32X has local SDRAM and two separate frame buffers. VDP1 was made specifically for dealing with SPRITES, while VDP2 did the background layers; on the 32X, the MD would do the background layers instead.
It's just wild speculation, but it does make some sense in the context of the times. Such a system actually may have been better in the long run than the Saturn was.