I mostly bodyblocked in very easy and easy, because swinging felt like a coin toss with my poor timing. Won by the CPU embarrasing itself. This stopped working in higher difficulties. I think that there are several ways to make the game easier, but they all will compromise the balance you are looking for right now. Some examples:
- Don't deactivate player hitbox while swinging, this way timing wont be as punishing. Place a mechanic which punishes the player after they get hit a specific number of times, which can be adjusted per character.
- Make bodyblocking the regular way to return the ball (removing hitstun and predictable slow ball) and give an advantage to the players who can time properly.
- Remove build up so hitting the ball becomes easier (what I suggested in the other post)
Increasing the hitbox could also work, but it would need to be a large increase. Anything you do will feel alien at first because you already know how to play and since you are the dev you must be the best player in the world right now. But bringing the skill floor lower will be helpful so people don't feel they suck after losing to the very easy bot and can focus on learning how each character plays instead.