Just one note on the missile that will be used in the Avangard system. There have been speculations that it will be the new Sarmat, but apparently that's not the case - the boost-glide vehicle was associated with UR-100NUTTH/SS-19 from the very beginning of the program in the 1980s, it used the missile during the tests, and will stay with it until the end. Russia got about 30 "dry" UR-100NUTTH missiles that it received from Ukraine - since these missiles have never been fueled they have a few decades of combat service in them.
(1) This would render both Sarmat and Rubezh development of little use. I dotn buy it. Unless there are other ways to deliver warheads. Cheaper ones - using Kiznahl tech.
(2) Avangard production rates must be really impressive