You can look to Ayuso, another rider coached by San Milan.
Vingegaard improved more between 2020-2023 compared to Pogacar for example so I don't know where San Milan is/was considered a genius. Specially when it is known Pogacar wasn't doing heat training and strenght training. San Milan is a researcher/teacher (they are important though), not a coach. Sola is a worldclass endurance coach. He is on the "field" with multiple athletes from cycling and triathlon.
João is also coached by Sola (and a portuguese physiologist. It's a team work) since 2024 and it's notorious his improvement.
Are they doping? Of course, but I don't see UAE in front of teams like RB, Lidl, Visma for example. Not just in doping, in other areas like nutrition, aerodynamics (e.g. TT setup), I don't see them in front of other top teams.