SJS, I think you may be convincing yourself that Rabbanim respond in matters they feel they are unqualified. In regards to the ear infection, the rav will say go to the doctor because he is an anav and not like the rest of us who feel we can make decisions based on nothing. We feel we are chachamim today because we know medicine or stock markets or whatever your field is however we are exactly the opposite. However, if they feel they are qualified to speak about this shidduch, they 100% should because they know emes. Never doubt a work spoken by a talmid chacham you have choosen as your rav or else you have not placed all your confidences in him and aseh licha rav has not been completed. And those that don’t properly trust rabanim cannot properly trust Hashem. (I’m not infering anything just making a general statement.) Rabbanim will also rarly say drop the shidduch unless the feel there is an extreme nesecity; rather, they will speak to you until you have come to a firm desicion as I know from experience.
Rabbanim don’t speak when they are not certain. The problem is we do and therefore believe the rabbanim are like us. We speak divrei leitzanut while they speak emet and that is just the way it is though they’d never agree.