Albert had long learned through internal channels why the Death Eaters were creating Inferi in large numbers. Though it was related to Snape's suggestion that the Death Eaters conserve their strength, he could not pin all the blame on him.
Snape was not a professional scapegoat, after all.
Hogwarts's new headmaster simply did not want the Death Eaters to clash head-on with the anti-Voldemort forces and drag Hogwarts into the conflict again, because he had promised Dumbledore that he would do everything possible to keep Hogwarts students safe.
No one had expected the Death Eaters' interpretation of conserving their strength to be this kind of conservation.
In truth, it was not that the Death Eaters wanted to conserve their strength this way. They simply had no other choice.
Since the Hogsmeade Incident, having learned their lesson, the Death Eaters no longer dared to rashly recruit more Dark Creatures.
Without the Dark Lord to keep them under control, continuing to recruit those Dark Creatures or Dark wizards would only cause them even greater trouble.
Organize Dark wizards for intensive training like the Defence Association?
That was even less possible.
Even the Dark Lord would probably have found that difficult. Otherwise, those Dark wizards would not merely be Dark wizards—they would be well-trained Aurors.
After giving up on those Dark wizards, the Death Eaters soon delightedly discovered that creating Inferi was indeed a good solution. They were vulnerable to light and fire, but even when ordinary wizards knew their weakness, destroying a single Inferius still took some effort.
Once their numbers grew large enough, most wizards would have to run even if they knew the Inferi's weaknesses.
Even if people from the Defence Association and the Order of the Phoenix came to make trouble, they could let them slowly deal with it.