Given the season, one might have said "a rafter of Hainsies" wished him well.
Of course, one could choose any number of words dependent upon how one views the "collective" at any given time.
For instance, should someone find us a bit devious, one might say, "An unkindness of Hainsies/Kimlets wished you..."
If one thought we were a bit viperish, one could say "A slither of Hainsies/Kimlets wished you..."
Should one view us as rather along the line of rodents, one might say, "A mischief of Hainsies/Kimlets wished you a..."
Of course, we are a playful lot, not unlike otters, so it would be apt to say, "A romp of Hainsies/Kimlets wished you a Happy Birthday."
Words can be such fun.
