Any of those guys you listed could carry the power potential to the majors. Broadway is probably the guy closest to the majors with a swing that could result in HR. Alot depends upon the new ballpark design. Right now, none of the Nationals minor leaguers have the necessary power to hit for power at RFK. Keep an eye on the doubles numbers of Nationals' minor leaguers because that is a good indicator of future power ability.
There are some interesting hitters in the GCL nationals team who have power potential.Like, Timothy Pahuta and Ryan Delaughter.The gulf coast league...is really really far from the big leagues but Delaughter seems to have a powerful swing, he strikes out too much but imo, he has some interesting power potential, same for Pahuta.
Diaz is the leader for doubles in the Carolina league.He has interesting potential!
A question...what's the venezualan summer league? I saw, we're sharing a team there with the Marlins....do some players there belong to us?