2018-12-07 : Any abilities that trigger on the Homunculus token entering the battlefield will resolve after you’ve sacrificed a creature.

2018-12-07 : The creature you sacrifice for the ability of Stitcher’s Apprentice could be the Homunculus you’ve just created. It could also be Stitcher’s Apprentice itself.

2018-12-07 : You create a token and sacrifice a creature all while the activated ability is resolving. Nothing can happen between the two, and no player may choose to take actions.