Do you say concordance of A and B, concordance of A with B, concordance between A and B, or something else?
According to this Google NGram, all of them are used but concordance of is most common:
However, this provided me with an originally false conclusion: the uses of concordance of refer to the use of concordance as an index, rather than "an agreement". Looking into the actual results in Google Books of "concordance of", the other definition of concordance is being used. Thus, in order to express "agreement", use concordance between as in "there was an agreement between A and B".