Compatibility is controlled by many factors and if two people are strongly attracted to one another you can bet that there is a relationship between Venus and Mars in their respective charts. Even bad relations between these two can result in passion. ....that can turn into passionate arguing.
You really don't even need another person invovled to have relationship issues. It is interesting how often love/hate relationships develop when someone has Venus and the moon or mars at odds in their own chart. A good example of this is when Venus is in a security loving sign like Taurus and their moon is in Aquarius which wants total freedom. Often these folks will pick someone who is a secure mate and then turn around and blame them for feelings of suffocation....Or they might partner with someone who wants an open relationship only to become increasingly insecure with that arrangement over time. They may grow too old to care why this happens before they figure it out.
There are two basic types of relationship chart. In one you compare the two charts. In the other you create a chart using the midpoints from the two charts. The first type gives you a good idea how the two will get along. The second is more about what the relationship as a whole is about and what they will do together.