I recall that they call the afterlife the pure land. If reincarnation works in that souls come and go from one world to another, then edo tensei wouldn’t be able to actually resurrect anyone as the souls themselves would be beyond reach. However, what if when souls passed on and reincarnated the memories of their lives were what was left behind. This would mean that the afterlife of various worlds would actually contain souls, but the part of souls where memory was stored. This would make it so that when a technique like edo tensei was used, the memories and personalIty of the deceased overwrites that of the living. This in turn gives the appearance of having actually resurrected someone when you’ve essentially just erased an the old program and downloaded a new one. Or not. Just a theory for others to consider.

Clearly a frog in a well, a toad that dreams of eating swan meat.