And no imagine how fast the 603 on your Blizzard would be if it hadn't to drag that 040/060 around ... and more important, how much cheaper those cards could have been.
Having a chipset (OCS,AA or Natami) around in a nextgen-Amiga is pointless as pretty much all SW needing it runs better on a full UAE-setup, RTG-SW runs much faster on Radeons and even if you could put a chipset in there, the restriction on timing and addressing introduced to the whole system would be counterproductive.
Adding an 68k-CPU would make things even worse ....