I think it is more plausible the way it turned out. It is easier to become 'friendly' with someone you know better. The Klingons are much more above board - you know what you are getting with them so it is easier to adjust, even diplomatically, to be able to deal with them. With the Romulans, you never know what you are getting. The Romulans are the ultimate 'sneaky snakes'. It is harder to come to any common ground - and even if you do, you are always second guessing everything that happens. The Typhon Pact books are an excellent example of that.