Blaming stalls for that situation is not necessary.
Plenty of horses do fine in stalls.
It doesn’t seem to be the stall, but the neighbor, that sets him off.
A friend trainer has a set up with stalls and runs off stalls.
The runs have thick wood slats between horses so they won’t chew on their neighbor’s manes/tails, as she gets many colts to start under saddle.
This one mare had been there a while without any problem, when they put a new gelding by her.
Next morning, she had kicked those boards off the fence, broken some!
She and gelding were fine, the fence not so much.
They moved the gelding to another place, all was well after that.