You could go with an 'eyebrow' overhang...look at My Coop page.
....or just go out a foot and put a larger fascia hanging down below rafter bottom to help block the weather.
Where are the hail pics?
Don't think you have TOO much ventilation.......but definitely not enough over hang.
Bummer...sorry you had such an event....
.....but, can't help laughing that you were both in the coop during the storm, I guess that made it very clear to the BF that he should have listened, huh?
Extending...