Shai Gilgeous-Alexander is in the dream position.  He’s the reigning MVP and his Thunder are the reigning champions. He’s expected to repeat for that honor. His team is, too.  That should’ve been Luka Doncic .  Luka Doncic and Shai Gilgeous-Alexander were both drafted in the 2018 class — Doncic at No. 3 and Gilgeous-Alexander at No. 11. Getty Images In a cruel twist of fate, Doncic will be on the bench Tuesday night, watching the superstar whose trajectory was supposed to be his as the Lakers opened their second-round playoff series against the Thunder in Oklahoma City. Doncic, who’s out indefinitely because of a strained hamstring , was supposed to be the young hotshot taking over the league. But his mantle remains empty, while Gilgeous-Alexander’s is decorated with the league’s most prestigious trophies. Doncic and Gilgeous-Alexander were in the same 2018 draft class.…