With thrillers like Thief, Warmth, and Miami Vice, filmmaker Michael Mann approached the “cops and robbers” style from an askew angle, packing easy tales with romantic yearning, coded language, and odd tangents. So it isn’t a shock that Ali, his model of a “sports activities film” and a biopic starring Will Smith as a result of the fighter, is an daring, occasionally strange clashing of tones. Instead of making an attempt to tell Ali’s life story, Mann burrows into specific conflicts – stress with spiritual leaders, a thorny relationship with the media, and a unstable love life – and creates…