No one/country needs 5000-6000 nukes, it's insane. Unless you plan to destroy other countries that are neutral out of spite, of course.
China is building 1000 nukes, not 5000, for a reason. I argue France has enough, and so does the UK. Russia is their only threat, and I doubt Iran would use nukes to do anything but argue about sanctions with the EU, because if they say nuke Berlin or Paris, they can kiss European demand for their exports away.
Russia and the US should have like at most, 2000 each, and even that's too much. They both have subs and ICBMS, so even if the bombers and strike craft are destroyed, they can still destroy each other's military targets and population centers.
Russia needs to deter Japan, the EU, China, and the US. The US needs to deter North Korea, Iran, China, Russia, and maybe Pakistan. The UK needs to deter... Russia, same with France. The bigger problem with the EU is that their ships don't have enough VLS(Missile launching containers on ships) cells, and need more protection against swarming attacks like the Houthis' anti-ship missiles, plus drones supplied by Iran. It's also good they have two sixth-gen fighter programs; they should have had a fifth-gen one to force the US to make a better F-35, and a better, longer-range F-22, or even brought the YF-23, the better option given its better range, speed, but not cost.