I don't know how this could interpreted, but the God-Beasts series in the Night of Knives were clones of Eddie and Angra, right? Since Forbidden Beasts are essentially copies of their hosts when fully matured, what would this mean for the men that were turned into God Beasts? Did they go insane from the clash of their identities?
They were unstable genetically to begin with. The God Series were more or less Gear mutations without a stabilized form left from the corpses of soldiers who served as their temporary hosts.
The host ‘explodes’ upon their birth, so even if they used humans as the base they were based on copied data from Angra and Eddie that was mere extracted DNA and not a full replica.
Functionally a Forbidden Beast can still work in synch with their host, as Eddie has proven with Zato, but that assumes their genetic 'base’ is stable and meets the parasite’s requirements.
Only certain subjects can become ideal hosts.
Just grafting genes from a compatible host on to the subject isn’t enough.
In other words, what you saw wasn’t anything resembling the inheritance process in true Gear Conversion.
What the God Series had wasn’t a true 'consciousness’, more like a command subroutine or an “If > Then” statement (less if using animal instinct).
If the last thoughts in a Soldier’s brain are to kill a target, then the parasite MAY inherit that thought, but not much else after that. It would be impressive for an unstable creature to retain any sort of shape or organic functions in that state, considering the corpse source material.
Basically, copy-grafting DNA isn’t the same as culturing it, and Gears and Forbidden Beasts are no exception to that rule.
Eddie had to 'grow’ in Zato and take his eyesight in order to function, there was no shortcut in that process. The same goes for true Gears.