Air China's Quirky Subsidiaries

Sorry for the mild spam
Saw an Air China Inner Mongolia 737 on flightradar24 and decided to investigate further!
Most of these are pretty well known apart from Air China Inner Mongolia, I found that interesting.

AIRCRAFT INFORMATION (up to down, left to right)
B-5392 - Boeing 737-89L
July 2008 delivered to Air China

B-1217 - Boeing 737-89L
June 2018 delivered to Air China Inner Mongolia

B-5553 - Boeing 737-89L
March 2011 delivered to Air China
December 2011 delivered to Dalian Airlines

B-5106 - Boeing 737-87L
June 2005 delivered to I dunno, planespotters.net doesn't say
October 2017 leased to Shenzhen Airlines

B-8417 - Airbus A320-212
July 2016 delivered to Tibet Airlines

B-MCH - Airbus A320-232
April 2017 delivered to Air China
March 2018 transferred to Air Macau

B-3999 - Boeing BBJ 737-79L
May 2011 delivered to Boeing Business Jets
August 2011 delivered to Lufthansa Technik
April 2012 delivered to Air China (operated by Beijing Airlines)