I don't have Dimitrov in the top 3, even after I revised it.
First, when I consider Sinner early in his career (and I would say I'm weighing this year more, but definitely considering whole careers), many of his losses came about due to an athletic deficiency of some sort. He was always good at beating lower ranked opponents, but Djokovic really just outlasted him at Wimbledon, Zverev at the US Open, Alcaraz at the Open.
Under his new team, [insert obligatory doping joke], his balance has improved, although his background in skiing already gave him a natural advantage. And I don't think clostebol is responsible for that.
He's got sonic power, good speed [but like Dimitrov, other factors play a role], and great balance and good flexibility, although other parts of his game compensate for some weaknesses. Stamina-wise, it's a bit hard to say, because he hasn't really been tested this year.
Medvedev has good stamina, great body control, and might actually be faster than Sinner. Powerful serve, but even he's candid about his lack of power on ground strokes.
Dimitrov beats Medvedev on power [except for the backhand], both on body control, and Sinner on stamina.