On the use of Strength, and other natural attributes
The lighter guys need to use strength in a far more intelligent and discriminatory fashion. They cannot just use it when they want to but must work the angles to make what they have more efficient
The bigger guy can get away with more, knowing that his strength can protect certain areas with less effort. And if worse comes to worse they can always access that strength difference to gain the advantage
Is this wrong? No, not at all.
If your natural strength can be used in an advantageous way, then, by all means, use it. I definitely do when and if I can. Just as if you were more explosive or flexible, then you would use those attributes
The trouble comes when you are countered by someone who is equal in those attributes or when they can use one or more of another attribute to stuff your game
King of everything then becomes intelligence and efficiency, knowing which skill set and approach to deal with what your opponent presents you with. In other words Strategy
So what will make you more intelligent and efficient? The ability to move.
The ability to follow/hunt/chase/force/maneuver your opponent into submission positions
The ability to
avoid and counter being followed/hunted/chased/forced/
maneuvered into submission positions
So focus on your movement, and use your attributes as an auxiliary supplement instead of the opposite way round.