Regarding the synchronization, you're right, it was all about balance in my fanon.
> Less than 100% means the I.S. do a lot of job supporting the pilot and not operating at full capacity.
> 100% (S) means full synchro, optimum, near-flawless operation. OOA can be manifested during this condition.
> More than 100% (Over S) means the pilot began to take over the I.S. themselves, forcibly making the I.S. develop prematurely. It does grant monstrous performance, but it also has all sort of risk and drawback. Think how Amuro Ray overworking his Gundam by sheer reflex alone.
Regarding the 'three cores' bullshit it was mostly spur of the moment, and indeed really redundant. The reason of his sync ratio looping back is because newer I.S. are specifically designed to PREVENT Overshift, which is why the I.S. overworked just to suppress his influence. But from Meta POV, it's done to make him sounds overpowered
As for the classification of his I.S. in the original concept, he does merge with the I.S.
physically, but they still have two separate soul than sync together. So you can say it's more like 6.5 generation. Of course, this means that the original concept
doesn't have >100% sync ratio most of the time, similar to the parents. And there's no anti-Overshift mechanism developed either.
