In recent years it has been expedient and professionally necessary for Chiwenga to be seen to support Mnangagwa, especially in supporting Mnanagwa's aspirations to take over the Presidency from Mugabe. However, he is deeply uneasy about tying his own political aspirations to a Karanga.
While content to hide in Mnangagwa's shadow in support for his presidential pretensions, I have it on good authority that he has been making plans to succeed Mugabe himself. It has not been difficult to build his own plans around the contingency planning for Mugabe's death which relies heavily on the military. Mnangagwa will only realise when his own plans are well advanced that Chiwenga has had a different agenda.
This is not merely a question of Chiwenga feeling more secure with the current Zezuru ascendancy - as a former supporter of the Mujuru camp, he feels that he will be better placed to unite the party behind him than Mnangagwa. Indeed he has come to believe that only he can save Zimbabwe from being torn apart by the factionalism within ZANU and the struggle between ZANU and the MDC.