Not many enormous nukes out there (>1MT). Russia has modernized to about 370-450kt on most warheads since the CEP has narrowed to "bullseye" capability on ICBMs and SLBMs the last 20 years. Only the Chinese have yet to reveal what they are doing with their warheads. My bet is that since President Kringtong gave them W88 warhead designs, they are pulling their >1MT warheads off and putting on 3-5 250-500kt warheads which actually does more damage than one big warhead.