Meaning if your prone, you should have a similar disadvantage that applies if you under sleep and get hit by a melee strike.
So like in 5e. Melee attackers get advantage against prone enemies.
Then cool, sounds like a balanced idea. I have only done some research on 5e, i was just responding to what was posted. But in regards to dodge, they should limit the amount of times you can use it, say 1 every 2 or 3 rounds. Otherwise it can just be spammed and exploited. That is if it is a bonus action.