Jose Abreu came from the exact same league right to the bigs. From all accounts, that league is probably in the A+ to AA range. I remember Red Sox took some ripping with starting Moncada in the SAL.
Rangers have alot of wingers though. I wouldn't be shocked if they take Byram. If they do take Kakko, Hawks have alot of options they can go (Podkolzin, Byram, Turcotte, Cozens, Dach, etc).