A Belgian Malinios will excel at speed sports, a Rotweiler will fall short. A Rotweiler can outpull the Belgian Malinios. A Belgian Malinios can herd; Rotweiler would probably ignore the other, or possibly try to drive the Belgian Malinios.
I can say that Belgian Malinios is equally needy. They are highly intelligent, sensitive dogs that require knowledgeable handling. Rotweiler are slightly lower in drive, energy, and intelligence, making them slightly easier to manage in some aspects.