When I see a lot of this voice replication I am reminded of something. (Dune series spoiler) For example, Duncan Idaho keeps being brought back with cloning tech, over and over, for centuries, because Leto II just likes him. Over and over, the same man keeps being put by the (nearly) immortal emperor's side... I ask: are we stuck as a monoculture, not making new, interesting things, but simply replicating older ones?…
I mean, there's a whole lot more to it than just that. Duncan is a key figure to The Golden Path Leto's breeding program. Without Duncan, the success of creating Siona is hollow. It's their nine daughters and thousand sons who are the human protection from prescience.