The Rangers’ minor league system is not a strength right now, but the folks at Fangraphs do see some things to feel good about. In particular, they are more bullish than most, I think, on Yolfran Castillo, who they have second in the system currently, and Paxton Kling, who they identify as a dark horse top 100 candidate for next year.
Overall, the system is heavy on arms and light on impact position players (outside of Sebastian Walcott, of course).