Film Reviews: Experienced Yank-born documaker Liz Mermin (“The Beauty School of Kabul”) tracks the progress of three young Irish racehorses over the course of a year in the engaging, steadily paced Irish-British co-production, “Horses.” Pic’s charismatic protagonists (both human and equine), crisp editing and elegant lensing foster engagement with a narrative that doesn’t dumb down the racing world’s complexities. Late January release should have a brief canter through Blighty’s arthouse course before heading for upmarket cable stables, though the helmer’s rep may ensure a couple of laps at specialized fests.