Hitler didn't have to. They basically encouraged themselves.

But your question is oversimplifying. It wasn't just Hitler Youth vs. "Scouts"

I'm going to get some details wrong, but here's how society was split up.

If you were a kid in school, and your father was a communist, you: Were "Red" played on the Communist soccer team, were a "Pioneer" and your dad was in the KPD (communist party)

If your father was in the SPD (social democrats) you: Were "Light Red" (Rose red, or "pink" derogatorily), played on the Soc-Dem soccer team, were a "Pfadfinder" and your dad was in the SPD.

If your dad was a nazi, you were: "Brown" or "brown shirt" played on the nazi soccer team, were with the "Hitlerjugend" (Hitler Youth) and your dad was in the NSDAP.

Everyone was brutal to everyone else. The kids did not mix. Not even KDP and SPD, unless playing soccer.

The political divides went from the parents to the children, to the schools, to every corner of society. "Pfadfinder" and "Pioneer" envied the "Hitlerjugend" because he got a kick-ass dagger and a snazzier uniform... in the 30's there just ended up being less "Pfadfinder" and "Pioneer" scouts and more hitler youth scouts.

...again, forgive me on the details. The point is it wasn't just scouts. And yes, that totally happened. Hitleryouth's big tactic was being a hard bully.