A wild Hand on Into Bridge

I am currently on the level King ♠, struggling to become an Ace. Today, the hand above happened. On its own, it looks strange enough. Would you bid 5♣ on North? It turns out that 5♦ make because the hearts can be established. That is not easy to see, but likely. Maybe, Lia on North has found this by simulating probable hands.

On my table, however, the South player decided to pass the negative double. The result was 1♠X+3 which is less than my 5♣X-3. You got to live with that kind of disappointing luck on the other side.

Now, what happened on other tables? I would have lost against each of them, because they played 3♦-5♦, sometimes doubled. Here is a typical bidding.

The difference to my biddings is that South did not repeat clubs. I considered 1NT too, but the spade control looked too bad, and Lia plays the negative double with very little. Others opened 1NT, or doubled 4♦, like in the following bidding.

I thought about this hand for while. The simple solution is to ignore the flimsy 4-card heart suit and to bid 3♣ right away. That would be a preemptive bid to keep the other side out of business. It might not work, because they still throw in their diamond suit somehow. But to find 5♦ is harder then.