Twice very recently I’ve been part of a discussion about these three views. Likely there are others [ e.g., tell nothing], but this three cornered choice is difficult enough for many of us. Certainly so depending on position/profession. And on the context. The two were in I.T. groups, in large business organizations. I believe that to reap the benefits, and effectiveness of a superb “Internal Consultant”, one must be able to “stir” ….actually customize, that mix to the person(s) engaged, and arrange for a second[ or more] conversation to expand or deepen the response. It may be that the proper mix will always be subject to change. Some lessons from past attempts…..1] impossible not to combine,i.e., to have zero of one view….2]improper to short the “should” view in favor of the other two [ time and pace help here]……3] Like always, preparation and follow -up are often more effective than actual content. 4] It may well be that first interaction is only a preamble, hardly ever an “answer”…so “cooking time” is crucial for acceptance.5]”Can” hear is more central than it may seem..sometimes people are simply incapable of hearing a particular view they don’t want to hear & continuing wastes everyone’s limited resources!!