As a suggestion, and strictly just a discussion here,
I don't wish to make anyone mad 
, CB could be based upon blocks of range. For example, Syria has 130mm guns with 217 range, while Turkey has 175mm with range of 227, so Syria can never CB Turkey but Turkey can CB Syria (in my game I have routed/destroyed 7 of 10 batteries with CB).
In the block suggestion a block could be 150-199, 200-250, so any battery with a range of 200+ can CB another battery within the block, in this case 227 with a battery of 217 since batteries do not deploy at extreme range. A battery with a range of 175 cannot CB a 200+ but the 200+ can obviously CB anything down the ladder.
OR: remove individual battery ranges and set all to a like, so anything with a 200+ range is set to 204 for example, while anything with a 150=199 is set to 175.
I don't know if block range could be coded in, but I do know that battery ranges could be changed, and I am more then willing to help or do it myself if the idea is considered to have merit.
I only bring this up for 2 reasons: 1. Batteries do not deploy at extreme range as they would not be able to support the advance if they did and 2. Checking Syria artillery he can never CB me which makes him defenseless, as my 175mm out range anything he can buy.