184.108.40.206 was release in Jul 1st 2009. You need a WCS version released AFTER Jul 1st 2009 and to be at least 4.2 code.
You need to wait for the next maintenance release of 4.2 or 5.2 or 6.0 code. Soon there should be a maintenance release for 6.0 and that will work with 220.127.116.11M.
You should be able to have mesh and non mesh controllers in the same mobility group, and you can keep 18.104.22.168M if you want.
22.214.171.124 is not a MESH code that I am aware of, as there is no mesh code after 4.2 of my knowledge.
If you want to use 126.96.36.199M Mesh and 188.8.131.52, then you need WC 184.108.40.206. The upgrade from 220.127.116.11 should take you about 10 minutes and will not loose any data, you will need to upgrade your WCS for this scenario to wok as 18.104.22.168M was released AFTER 22.214.171.124 but BEFORE 126.96.36.199