While you do have the time frame correct, the western powers did not force CENTO.
CENTO started more or less with the Baghdad pact; which was a mutual defence pact created between Turkey and Iraq. I only state more or less, for Turkey and Pakistan already had an agreement (wouldn't want to step on any history fans feet :) )
Then Iran joined; then Pakistan, and then the UK.
Stating that the west strong-armed or dominated it is a vast exaggeration, if anything it just instilled more fear into the Soviet; which is why the U.K. (a little ironic you have the problem with this :p) wanted it soo badly. It was another attempt to contain the Soviets from any access to oil.
Although it did eventually fall through(~1970s) Middle Eastern nations did create mutual defence pacts. This is seen not only with the Baghdad pact, but with the Arab league.
The Joint Defence Council (that you state is unrealistic) is the EXACT name that the Arab league gave when it was formed in 1950 :)
The Arab league had Egypt, Saudi, Iraq, Jordan, Syria, Lebanon, and Palestine as members (all of which are in attendance of this "unrealistic" meeting)
These were all members of the Joint Defence Council. Even if any of the nations hated each other at the time, they still pledged to defend one another for their own safety.
Now back to the time frame, yes it is a little bit early (for CENTO not the Joint Defence Council) but if you take the In Game events it makes complete sense.
Persia was INVADED loosing half of their nation. This is exactly the thing nations fear. If anything would hasten a mutual defence agreement it would be a super power taking bites out of your neighbor.
I mean you haven't contacted the Scandinavians who are attempting to do what we are, but with a GDP requirement to military spending (which is roughly triple what their nations spend on GDP today).
So with all of that being said can you see who this is actually realistic, especially for the game?
/u/Zaldax /u/TsarPerhaps /u/XeyBlazey