Marchiso's best season in the regista role for us (2015/16) vs Pirlo's worst (2014/15):
Assists: Marchisio 2, Pirlo 5
Keypasses per game: chisio 1, Pirlo 2.2
Avg # of passes per game: chisio 63.5, Pirlo 72.7
Pass success %: marchisio 88.5% , Pirlo 89.2%
Dispossessed: chisio 0.7, Pirlo 0.7
Tackles: marchisio 2.1, Pirlo 1.6
Interceptions: chisio 2.8, Pirlo 1.5
So when you look at the stats for both, chisio at his best in a full regista role season playing 352 vs Pirlo at his worst changing between 4312 & 352, Pirlo passed the ball much more frequently, was slightly more reliable passer (less mispasses per game), much more penetrative passer, and was as frequently dispossessed holding the ball as chisio. Chisio was much better in winning the ball back when someone else had lost it other than himself and in intercepting opposition passes.
So the reality is that you are heavily exaggerating when you consider him unstable magic. He was at his worst less likely to lose the ball by a miss-pass or by being tackled. The distance becomes even larger when you look at Pirlo's best season as regista 11/12. He made 13 assists, 3.4 keypasses (chisio's 1), 86.4 passes per game (chisio's 63.5).
So PI is right, Pirlo's god mode is just that God mode. Probably best regista in history and obviously better than chisio by a margin. We felt he regressed because he actually did regress compared to his own old standards. He was still a great regista (we wouldnt have made it all the way if he was shit like hernanes/lemina) just not as good as what we got used to from him. He certainly was no unstable magic. He was as unstable as chisio was last season, which is pretty fucking stable if you ask me. Our defensive record throughout the pirlo era was very good under both coaches every year.