There are a lot of different aspects of relationships that you can rank. For general compatibility, having complementary ego functions is best. If they are the same it helps too. Also (generally) within-quadra > adjacent quadra > opposite quadra. It's hard to rank them because often I like my conflictors, for example, but if we had a closer relationship it would go terribly wrong.

Also, I un-recommend Ganin's site. He oversimplifies certain aspects of socionics and totally ignores others. His articles hardly even talk about information elements.