Understandably, there are differences between lineages because each person is unique. Say for example, there are 20 kids in the class. Their teacher taught them how to write the alphabet. All 20 kids are taught the same thing by the same teacher. But if you ask each of them to write the alphabet, there will be 20 different A's, 20 different B's, etc.
Now, how did that happen?
Defend where there is no attack; attack where there is no defense.
Attack is the secret of defense; defense is the planning of an attack.