if I have {conspiracy} out with the creature type of scarecrow called if I had a way to copy it in edh and called myr would it stack both type or would they just keep replacing each other?
As I read it.....The ruling states it loses all other types so they would not stack.
Because all other creature types are lost, the effects are applied in time stamp order, effectively giving them the creature type of the most recent spell. In this case, all your creatures would be Myr.