It's a blog and I've no idea if it's accurate but it seems credible, it's based on his last big job at Sampdoria.
https://doriastyle.wordpress.com/2015/11/09/zenga-making-sampdoria-mediocre/
Positives:
Teams play 4-3-1-2 or 4-3-3
Doesn't like wing backs or overly defensive play
Teams are far better attacking at pace and with possession
High goal scoring team
Likes open and attacking play
Negatives:
Can't settle on a formation
Struggles playing people in correct decisions
Odd team selections
No pattern in team selection
Poor defensively and poor in possession when playing defensively.
Cannot play defensive football
If he plays open attacking football it may be that he should be more suited to England than Italy. At least I hope so.