How to fit DNA matches fit into one's tree

The group has been quiet, so I figure I could post a more speculative
question.

I've taken a Y-DNA test (as well as the mtDNA test), and I have about
15 matches.  One of these matches is a relatively close match (about 7
generations away), and I'm hoping to find the exact connection soon.

While a few of the other 14 matches have similar beginnings of
surnames, it's probable that the connection is further back in time.
Considering that I'm Jewish and my paternal ancestry is from Belarus,
I would think it's an almost insurmountable task to trace people prior
to the beginning of the 18th century.

I was struck by a recent statement someone made, something to the
effect of if there is no do***ntation for the person, then they don't
belong on your tree.

For those who have achieved simliar results through DNA testing, what
do you do?  Incor****ate the people into the tree, or do something else
with them?  

I'm interested to hear of others' solutions.

Bob Kosovsky
New York City