As Lynda mentions, the number of chromosome pairs on which matches occur isn't particularly significant in determining a relationship. There are two "lengths" which are used for matching on gedmatch:
- a single sequence of length 7 cM or more on a single chromosome pair that is identical for two persons is a "match"
- the sum of the lengths of all such matches is the total length.
The total length of all matches provides an indication of the relationship (2nd cousin, great-grandparent, etc). So the number of chromosome pairs on which matches occur isn't used to indicate a relationship. However, a larger number of matches contributes to the total length, which is an indication.
Matches across several pairs of chromosomes is very useful, however, when you start mapping chromosomes to determine on which chromosome (X or Y) of the pair the match occurs. So, more is better for that reason.