If there is one thing I've learned about Russian technology then it is that in general it will operate 'good enough' to do what it was designed to do even if that means that it isn't designed in a way that we would consider elegant. Assuming that Russia's nuclear arsenal is dysfunctional or even non-existent would be a very large - and possibly fatal - mistake, especially given that it never was designed as a precision tool anyway but relied on massive overkill. You may well be right, but if history is any guide here making assumptions without hard evidence about the nature of an enemy arsenal, either positive or negative will lead to trouble.
I had a couple conversations with an engineer who worked a long career on maintaining nuclear warheads. I was rather surprised when he told me that he didn't view nuclear war as likely.
As he explained it, plutonium warheads break down over time. They create helium gas pockets and sometimes internal fractures that prevent detonation.
The solution is to reform the warhead every few years.
The problem here is that plutonium has over a dozen crystalline forms. If they don't achieve a uniform crystal, the warhead will fail to detonate due to the imperfections along the lines where the different crystals come together. This takes a ton of time and money (and often many, many attempts).
Together these mean that the warheads are getting very old and the upkeep to keep them working is huge. Russia can keep a few in working order, but not nearly what their previous arsenal would imply.
