City Neighbors Moral factor Control

It is effected by the neighboring provinces; meaning if Paris has low morale, Lille, Reims, etc, will all have a negative modifier to their morale (morale will not increase as quickly). Enough negative modifiers and morale will begin to drop lower.

I have all of Egypt Cities under my occupation

I'm Playing with Saudi Arabia

I toke 2 New Capitals in the same Day

Egypt Cities morals are 100 % all of them

in the same time

some Of Egypt cities has Neighbors Moral factor =+12

other one Neighbors Moral factor=+8

another on =+4

So it is big variance between +12 and +4

I was thinking Neighbors Moral factor could be affected or controlled

by keeping troops in each city

or Building Garrisons higher level

but I'm not sure of that

So is it out of control totally

how it come??

I have many cities the city moral is 98% ,99% ,100%

all surrounded with other high moral level cities of mine

no enemy cities beside any one of them

but some cities has Neighbors Moral factor=+12

other one has Neighbors Moral factor=+6 ?????!!!!!

was the city recently conquered or changed hands? bombed? or traded? spies can lower morale as well.