@summers base on my fair share of read isekai manga's
i believe the god(s) cannot intervene directly on the world they are managing so they just pull some spirit or soul of an another world where they are not managing. IDK why they cant maybe its a rule but it is possible to the world that they are not managing something like for example there are myths and shits like that on the world which can be because of an intervention of an another god like iseka'ing a monster to that particular world.
yeah something like that seems to be the case to me