Omaha-raised actor Zahn McClarnon has 30 years and 70 credits to his name, most notably scene-stealing roles on FX’s “Fargo” and Netflix’s “Longmire.” The 50-year-old actor has done a lot and seen a lot. But his latest project casts him in fresh new territory: playing Pierce Brosnan’s father. In AMC’s new epic Western series, “The Son” — which began its 10-episode season Saturday night — McClarnon plays Toshaway, the chief of a Comanche Tribe. During a raid, the tribe captures a Texas boy named Eli McCullough (Jacob Lofland, of “Mud” and “Justified”), whom Toshaway raises as his own. As Eli’s...