Joining 2 tables- in Select statement show how many fields matched directly (A1 = B1), vs matched on isnull(A1,B1) = B1
How about : 

CASE WHEN t2.A IS NOT NULL THEN 1 ELSE 0 END
+ CASE WHEN t2.B IS NOT NULL THEN 1 ELSE 0 END
+ CASE WHEN t2.C IS NOT NULL THEN 1 ELSE 0 END
+ CASE WHEN t2.D IS NOT NULL THEN 1 ELSE 0 END
+ CASE WHEN t2.E IS NOT NULL THEN 1 ELSE 0 END