For what its worth, everything is connected through the short building in the middle photo where the lobby, store, and some dining are located. You can walk between the two towers on floor 3, which is the main floor. Because everything is connected inside, IMO, the tower location is less important and nothing is a far a walk. The resort isn't as huge as I was expecting it to be.
As mentioned, Waianae is slightly smaller and is closer to the parking ramp, spa, Ulu Café, and adult pool. Ewa is closer to the store, Makahiki, AMA AMA, Aunty's, Off the Hook, and the lawn where the luau is.