...I'm trying not to take my frustration with those other two out on you since, near as I can tell, you're at least trying to argue in good faith. Anyway...
Given our opponents, we probably can't afford not to build for durability, best achieved by making the entire sword a single solid mass aside from the Arc stuff. I mean, given the choice between a sword that needs to be completely rebuilt when it breaks but it takes a lot of abuse to break it or a sword that you can just slap a new blade onto every time it breaks but you need to replace the blade with every swing, I'm going with the one that doesn't break (though to be fair it probably isn't quite that polarized).
The electrical components of the Arc Blade are in the handle, yes, but the blade itself must be designed to accommodate the electrical charge. Replacing that is trickier than people seem to assume, which is why I'm assuming that "repair" is more along the lines of "scrap what little is left of the old one and make a new one from scratch." I mean, yes, wiring is fairly simple at first glance, but getting it properly hooked up to the generator so it doesn't backfire is a delicate business- take it from a guy who's had his house burn down in an electrical fire. And if they're taking the handle apart to get the conductors properly attached to the generator anyway, that's at most a philosophical distinction from "scrap the old and rebuild."