True, but which is it? I mean, you asked two questions. (1) How they were as a couple, and (2) If the two together meant marriage. That doesn't necessarily mean they go together. For example, ift you did a spread and asked "who am I?" and got the Queen/Wands, then "who is he?" and got King/Wands then that's how you are as a couple. Dramatic and temperamental, but also warm, mature and still able to keep things passionate. But that doesn't mean that you're going to get married.
If, on the other hand, you asked, "where is this relationship going?' and got these two, then—if you're right and the pair mean marriage—then wedding bells are gonna chime. But if that's what they mean, than that's all they mean. The King/Queen of cups don't mean marriage. Nor does the Knight/Queen of Wands for that matter. Presumably ONLY the King/Queen Wands together signify marriage. Which means getting them in answer to such a question is like getting the 4/Wands. It has to stand for ALL types of marriages. For those that are whirlwind romance and those that took a long time. For those that are going to be loving and lasting and those that won't. For young couples and old, mature and immature. For those that will stick it out no matter what and those that will end in divorce.
If these two stand for marriage, then they cover any and all kinds of couples, not just King/Queen of Wands type couples. And all they're saying in that instance is: you two will be tying the knot. Not whether you'll be a good couple, a bad couple or any of that other stuff. Does that make sense?
My interpretation regarding their meaning marriage (rather than, say, the King & Queen of Cups or Swords) is that King & Queen of Wands might have earned this special, extra meaning because they are about passionate natures and newlyweds are passionate. So that's why I'd offer that advice to anyone getting them and seeing them as standing for marriage rather than standing for the couple as a couple.