I disagree with your perspective. I think forcing himself out of the ball with the adaptive shield is something that should stay as it helps with the flow of the hero, reinforces the flow of the hero, and that his ammo count is fine.
The shields are meant as a means to establish yourself in a fight, and to allow yourself a window to escape after going in. They are not meant to make you absurdly difficult to kill while outside of the fight.
Him using his shields to bring himself out of the ball to shoot at targets is very ideal. You are simultaneously bringing out your weaponry and defending yourself, instead of separately.
His shielding with fewer enemies nearby needs addressing. I legitimately see no issues with the rest of his kit. It’s all up to the player to make good use of them. If you can’t reliably track with him, of course his ammo count being only at 80 isn’t going to feel good enough. Ammo management is a big part of his kit.
If they took his adaptive shield and altered it to give 75 per enemy hero nearby and initially 250 (same max but more with less enemies near), I think it would be much better overall, much more applicable.
His exceptional mobility and crowd control options are very powerful in proper usage, but heavily countered by crowd control. This is a given, and is his primary weakness.
Overall, wrecking ball has a lot of potential with his kit. Unfortunately its just very difficult to justify the pick as his durability is unreliable.