The comparatives to what Miguel Sano has brought to the Twins are ancient when it comes to the franchise history in Minnesota.
For the impact of a rookie season, I would put only Tony Oliva in 1964 in the same category. He started off hitting second as a rookie in 1964 and did amazing things: leading the league in hits (217), runs (109), doubles (43) and batting (.323). He also had 32 home runs and 94 RBI. He received 19 of the 20 votes for American League Rookie of the Year, with one foolish vote being cast for Baltimore pitcher Wally Bunker.
OK, Tony O. didn't hit Sano's mammoth home runs, but his impact was enormous and he captured the locals' imagination as quickly once we got to see him in the lineup on a regular basis.
As for seeing power from a hitter with no previous big-league at-bats, the challenger to Sano would be Jimmie Hall in 1963. He came out of two years spent mostly in military service to hit 33 home runs with 80 RBI in 497 at-bats for that collection of slugging Twins.