Sunny, I would agree with everything the catalog article states, except that the diary entries re: Voronov begin much sooner than December 1913. Of course, I am only working with what my friend translated for me. But I trust his work, and given that Olga's November birthday party took place onboard the Standart, and that the family had visited Livadia and been onboard the Standart earlier that year--when Voronov was very much in evidence--I think it's safe to assume that Olga and Paul had enjoyed their mutual flirtation-turned-into-romance for some time before the engagement and subsequent marriage of Paul and the other Olga became a reality.
Those of us who have read the correspondence in A Lifelong Passion know that Alexandra already had written a tender but firm note to Marie re: her infatuation for an officer, reminding her that although it was not bad to feel that way, he had his life to live, and she had hers. (I am sorry not to quote this letter exactly and provide an exact citation; my copy of Passion is on loan!) We know that Nicholas and Alexandra had at one time thought Dmitri might be a possible match for Olga--and, as a grand duke, he would have been of far more appropriate "station" than a Standart officer--but of course they backed off when it became apparent that Dmitri was living a rather scandalous life.
The issue of their children's eventual marriages had, early on, been a "backburner" concern for both parents--and, as their daughters matured, would naturally have been an issue of growing concern, especially to Alexandra. (Most of us have read quotes to that effect!) Every parent has these worries, to a degree, but for Nicholas and Alexandra--and particularly Alexandra, who was very much the granddaughter of Queen Victoria--this issue was exceptionally complex. Any suitors for her daughters must be of a particular station, of course. Also, both Alix and Nicky did not want her daughters to marry without love. And then there was the issue of personal morality, which brings to mind the infamous attempt to match Olga with Grand Duke Boris! Had the war and revolution not intervened, the matchmaking for these girls undoubtedly would have been as complex as that re: Prince Charles of England, half a century (and more) later!
The other speculation, of course, is that if the Romanov dynasty had survived the war, the girls might well have been allowed a broader field of choice for marriage partners. (Consider the fact that Aunt Olga was allowed to divorce and marry her "commoner.") And if the dynasty hadn't survived the war and revolution, but the family had successfully escaped to another European country, the choices for OTMA would have been even more numerous . . . unless the reservations Queen Marie of Romania had re: the hemophillia issue might have influenced other matchmaking families as well.
The game of "if" is intriguing to play, of course!