Enhanced_CPC is a type of bidding strategy that raises bids for clicks that seem more likely to lead to a conversion. It also lowers them for clicks that seem less likely to lead to conversion. While for
Manual_CPC, it is a bidding strategy based on manual clicks where user pays per click. If
enhancedCpcEnabled is true, then it enables bids based on conversion optimizer data. You can check
here for more information regarding bidding strategy types.
In regards to how the Manual_CPC with enhancedCpcEnabled affect campaign children entities, I would recommend you to post this concern in the
AdWords Community Forum as this is more of a product level concern.