Helmut Lang did some interesting technical work, but it wasn't typically in the arena of tailoring, though I remember that he did some kick ass suits. His contribution was in his application of "Minimalism" broaderly speaking, in the 90s. He stripped down a lot of garments (see his jean jackets and his military jackets) to their core features (not just functional elements, which is a rather narrow way of looking at minimalism) and made some spectacular garments. Cloak, imo, was really about the styling. I like Cloak, but it really was not at the same level as Helmut Lang.
A lot of the "artisanal" designers are very intereste and invested in construction and the process of creation, and it is a lot of what they bring to the table, so it's unfair to say that they have "poor" construction, as if it was an afterthought. I mean, any designer can send things out to a factory, and they can get a garment sewn properly, no problem. It just isn't what they want.