I also mentioned he needs to improve his plate discipline and not hack at anything, which is definitely more important than homers, so that is my bad for how I phrased it.
Machado was already the best defender at 3B if you look at both DRS and UZR, so if he cleans up his approach at the plate and has some more power, there is no reason to believe he won't leap over Wright, Beltre, or Longo. Even a healthy Beltre in 2012 didn't match Machado's DRS and UZR ratings.