Good point about Sir Walter very likely marrying under the same circumstances as Col. Wallace describes! I only disagree a little about SW's ability to show good manners (at least temporarily). In ch.5 we are told that on first meeting the Crofts, Sir Walter has been "flattered into his very best and most polished behaviour by Mr. Shepherd's assurances of his being known...as a model of good breeding". Very likely he managed this (at least in spurts!) during the time he was courting the future Lady Elliot, too.