Woah now! 8 years? Don't you know how stressful it would be to release something in that short of a timeframe? Who said anything about 5.0.0 taking less than 10 years? 12 years would be far too demanding, we have to account for her mental health after all. It's awful demanding that you want it to come out a mere 15 years from now....
To add on to MSGTNP's comment, scarlet and brax have the same dialogue and options as generic slaves. I think that defeats the whole point of having NPC slaves, but you might disagree. If that's the case, I got a guide on cloning NPC's into slaves.