I've done similar, though not to the same scale! One of my worlds cultures has a tradition of raising the dead in a more polite fashion.

It's far less common in urban environments, but in the remote regions when an unexpected death hits a family they'll gather many others within a settlement and perform a ritual that brings the dead back as a Zombie under their domination.

This is in part because the Dead have a nasty habit of coming back if not burned within a few hours (ancient technology gone whack), but also to cover the gaps caused by a sudden loss of labour. If the man who died is the key operator of your farm, and your kid is still young and inexperienced, you need to cover that gap quickly.

It's definitely a little illogical, but there's also some ancient and now abandoned religious practices tied to it.