Not really for me.
I normally spam saplings all in a row, they'll neatly grow into trees with un-grown saplings still in between. When you chop the trees down the rest will sprout.
Just a little less effort, never had problems with it... though not one NPC has moved into their house yet, I've met all requirements :/
you have to do something special.
For a Dryad,kill a boss.
For a merchant,get 50 silver coins.
For a explosives salesman,blow up one bomb.
A nurse will visit without any special needs.
