The "peanuts" I meant relatively, but here it is not very dramatic: the knot lines only separate the pairs of plots from the next ones, for which a reference height that deviates by half a meter then applies. Strangely enough, for the garages, you have to coordinate them not with your own duplex partner, but with the neighbor on the other side (i.e. with a different reference height). You can build II + D here, although this does not have to be exploited; II without D would also be possible. Tell me more precisely about the plot dimensions. It seems to me that you have marked a pair of houses shifted here compared to the first sketches. Instead of page 4 of the development plan, you have probably duplicated page 3.
Building together with the partner is highly advisable; it is best to plan together as well. However, this does not mean that the same house formats have to be chosen, and here I even advise unequal ones: namely, in your half to fully utilize the building window depth and rather make the house narrower in favor of a wider west garden.