Usually if I was writing a Manatee Mansion-type story, script or game I would tend to have quite a large cast up my sleeve ready to roll out in a variety of situations. However the tiny number of dramatis personae so far in MM is really invigorating to me. It is forcing me to really polish them and make them interesting, special and unique, instead of just continually throwing more and more off the wall characters into the mix. Which is not to say there won't be "crowd scenes", but I like exploring the Cthulhu Noir* type trope and that means isolation and alienation, which is much easier to generate with literal physical loneliness where possible rather than "mere" emotional loneliness.
*see posts labelled "stuff I make up and trademark" :)