I don't spent much time on my road bike riding out of the saddle or "perched lightly" on it. Perhaps others do, but this the first I've heard of it. Of course, some people climb a lot out of the saddle (but I don't). It seems to me that regardless of the bike's use, having a saddle that is too wide for you is going to lead to problems. If I were you, I'd do a few test rides on your touring bike using your road bike saddle. If it feels good, buy a second one. If it doesn't, then I'd tool around here for some additonal suggestions.
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher