Rino is doing so well, and he hasn't even really done much tactically yet. Sometimes keeping it simple and picking the right style of play for your team(+mentality obviously) is more important than out thinking your opponents every week. Montella is a good coach, but he tried to rush the team into playing his way, and he got away from the more practical approach that made him so good last season.
Not that Rino doesn't have good ideas or is a tactical slouch though. He's just taking it slow and using a step by step approach, he has one of the most clear plans I can remember from our last few coaches. We probably won't see a true Rino team until next season when he has had an offseason and a transfer session to work with. I do really like to hear how he wants more players in the box though. That's so clearly how this team is built to attack. Hakan and RR left, Suso and Calabria right. Cutrone lives for space in the box, kalinic is decent in the air, Silva needs so much work but at least is strong and athletic. Jack and Kessie love to make those late runs in the box. Hell even Conti we know likes to get in the box. Milan doesn't have the creativity that Montella needed, this isn't stoke city but we can do some damage by flooding penalty areas I think.
Will say though, we will know more about Gattuso when the form starts to dip. He's done so great so far and he deserves a lot more time, but the team will face some setbacks that every coach of Milan has had recently, he is not the first coach to get the team on a run of form. I trust and believe in him, but the expectations are already started to get a bit too high, we'll see how he handles it