There are two types of people
self driven and non-self driven.
self driven people dont care about whats others opinion and just do what they think of.
For example.
if two self driven people marry. there may be clashes among them due to ego problems.
Though it could happen , if they respect each others thought and go accordingly they can avoid clash.
If two non-self driven people marry, again there could be clash in themselves bcoz of contradictory thoughts , so same is the solution for all types of people.
Clash occurs bcoz of disagreement to the statements,if the behavior is identified, and things suppporting to the behaviour is identified then clashes can be avoided.