Ham meeting Tubal-Cain scene

The scene was weirdly shot and didn't make much sense.

So you have ham hearing feminine laughs in the wood. He's looking and indeed sees two women running from left to right (close shot). Then a guy come out of nowhere in the camera from the right and tries to kill Ham. So:

1. Why would these two women laugh and run in the wood ? To set a trap ? Hard to believe, especially with what follows;
2. Ham was at the edge of the forrest, surrounded by not much, surely he would have seen or heard that guy coming close;
3. Why would that guy want to kill Ham anyway ?

And then, what makes even less sense : Tubal-Cain appears fron nowhere with 500 people and kill the attacker. Wait what ?

1. So not only two random girls run in the wood and one random guy appears from nowhere but all of a sudden a random King Tubal-Cain appears from nowhere to kill the first guy one sec later;
2. Tubal-Cain has 500 hundred people with him and Ham didn't notice ? Really ?