I've reconsidered it and decided to attach the waist pieces this way instead.
I think how I had it here
>>7520156 makes an opportunity to solidify the Gahlok shield way too obvious, which goes against my "accident" theory. If it were built that way, surely they would have realized they could connect the shield more solidly.
Doing it this way also means that he utilizes a total of 22 half bushings. I've put together a list on BrickLink that includes all of the sets I'm certain the original builder had and, among the titans confirmed in his collection, the total amount of half-bushings across them all is... guess what? 22.
That explains why there are bushings missing from obvious places, like in his shoulders or at the end of the axles sticking out of his back. He ran out.