Cofty: I have read the same in Frank Dikotter's trilogy on Mao and in Paul French's book "North Korea, State of Paranoia".
Thnx Cofty, I think that its a common belief, but Mikoyan gives some interesting details concerning the attitudes of the Soviets and China (in conjunction) to the methods used by Kim Il-sung to eliminate rivals and to take complete control of the Korean Workers Party. I assume this may be a reference to the death of Ho Ka-i, who Andrei Lankov calls, the "Forgotten Founding Father of the KWP.
As far as can be known, there were a number of factions in the DPRK. In addition to the Soviet faction (as above) there was a group identified as the Yanan faction, men who'd been in China during the war against the Japanese. Another group had been in Manchuria, others who had managed to stay in Korea itself for the war, and still others like Kim who the Japanese had managed to drive out of the Manchurian-Korean border zone and who had eventually fled to Russia for refuge. What their differences were, or their similarities may not be understood clearly.
Ho was an ethnic Korean born in Russia, who became the leader of the Soviet Korean faction in the first political structures in what we call NK. Ho and Kim seem to have had a falling out, that may have started in 1951. It is thought that the failure of the NK army to totally defeat the South Koreans in the first weeks of the war (You'll likely recall that they drove the SK army into a small 50 x 50 mile section around the Port city of Busan) . That gave the USA and its allies the opportunity to provide reinforcements to the south and in Macarthur's quite brilliant Inchon landing, allowed a pincer movement that almost destroyed the NK army, and since Kim Il-song had always pushed for a military solution (but so had Syngman Rhee) he may have copped a lot of flak. That nearly caused the defeat of the North and became the source of much internal stress and conflict at high levels within the KWP and the NK government. In any event Ho was supposed to have committed suicide, but may have been murdered.
Mikoyan also mentions that the Soviets and China made an attempt to assassinate Kim Il-sung. That surely must have influenced attitudes and behaviour for a long time
Whether, this can all be regarded as dependable, is (of course) a different matter.