So we have been playing OOB (with FAQ) in my group and we are still seeing the CPs getting dominated.
And we came up with a simple, yet not historical what so ever house rule to boost the CPs (after a bit of drinking)
We wanted to stimulate some naval action for the CPs, by giving them a free naval unit every once in a while.
For the Central Powers only, if you control your capital and the enemy does not contest or control any territories adjacent to your capital, then at the end of your purchase units phase roll a die and consult the following chart. You are awarded an additional free unit added to your purchased units.
1. Infantry
2. Infantry
3. Artillery
4. Fighter
5. Sub
6. Cruiser
The counter proposal to this rule was a National Objective for each of the Central Powers.
You collect an additional 5 IPCs if the Allies do not control or contest any of the territories adjacent to your capital.
We didn’t want to give the CPs a bid of raw units to put wherever they want, or that may upset the natural balance of the game. But we do recognize they are lagging behind the allies.