16-35 zeiss f4 is a great lense. Great color and contrast. Loxia 21 is even better especially in corner sharpness. I am nowadays using loxia 21 almost all the time with some personal preferences;
1) Prime lenses push me to seek for alternate compositions. In zoom I tend to change the focal range to find a composition. If I realize I tend to do this I of course change my position but sometimes you just dont realize and stay at your position and just play with the focal length.
2) Loxia 21 is much more compact and also great for street & urban photography.
3) I would also consider Milvus 15 mm with a Nikon to FE adapter. Nikon version of Milvuses have aperture Rings. (Loxia also does have).
It may sound again a personal preference but I really like using aperture rings, I even cant think off a lense without it even though its electronoical.
4) There's also chaaper but yet great options like Rokinon / Samyang 24 1.4 good
If I was to start a new kit I would go with one the following options.
a) the 15mm Milvus, 21 mm Loxia and 50 mm Loxia and then 100mm Zeiss Makro-Planar (Prime Options).
b) 16-35 f4, 24-70 f4, 70-200 f4 (zoom options - lighter & cheaper and does the job great).
HTH