Russian applied math books are the very best. The presentation seems to be practical and does not expect things to be necessarily pretty - there is lack of an agenda. Ironic, because I can think of Russian chess books that praised the Soviet system and the skill of the Russian masters as proof of it - so Botvinnik was great because he was Soviet, not because he was Botvinnik.

Physics also has many canonical texts from Russians.

No, it wasn't a matter of brains at the top. It was a matter of systems engineering - development, test, redevelopment, etc.