Different methods work. It's up to the individual. Fortunately, OP you've had great success with your small flock of 4. Your neighbor, unfortunately, has not. Any of us who have had several larger flocks know that success rates vary - and individual chickens differ within the larger flock.
To play devil's advocate, who's to say your next flock will do so well?
I see no reason for any sense of obligation to give anyone - including your neighbor - chicks that you hatch for no other reason that they belong to you. Nothing else needs to be said.