Obviously, his friends Ron and Hermione would be among the first to join. Neville could also be a key member, as he has shown great courage. Then there might be the members of Dumbledore's Army who are still at Hogwarts. The Weasley twins could also be part of it, using their unique magical inventions to give the army an edge in battle.
It's interesting because it combines two different worlds - the magical world of Harry Potter and the military world. It creates unique scenarios where Harry has to use his magic skills in a military context.
Neville would likely be one of the first to join. He has always been brave and has a strong sense of justice. Luna Lovegood might also be part of it. Her unique perspective and knowledge of the wizarding world could be very useful. And then there are the Weasley twins. Their skills in magic and their ability to think outside the box would make them great assets.
He could have found a magical artifact. There are many artifacts in the Harry Potter world that have strange and powerful abilities. It could be that this artifact has the power to create clones. He figures out how to use it, perhaps with the help of Hermione who is good at researching such things. And then he starts creating his clone army.
He might face opposition from the school authorities or other wizarding institutions. They could see his army - building as a threat. Also, finding resources to train and equip the army could be difficult. Magic items and training grounds are not easy to come by. And he has to keep the existence of the army a secret from the Death Eaters, which adds another layer of difficulty.
In this fanfiction, Harry might also include some of the Hogwarts ghosts in his army. After all, they have a long - standing relationship with the school. Peeves, for example, could be a wild card in the army. He can cause chaos among the enemies. And some of the older students who have a strong sense of justice, like Cedric Diggory's friends, could also be part of it.
There could be his drill sergeant, a tough and no - nonsense character who has to whip Harry into shape. Maybe there's a fellow recruit who becomes Harry's best friend. They could support each other through the difficult training.
Well, in this 'harry has a army of minions fanfiction', it might depict how Harry manages his minion army. Are they magical minions? Do they have special abilities? It could explore the dynamics between Harry and his minions, like how he recruits them, trains them, and what tasks he assigns to them. It could also show how this army of minions impacts the original Harry Potter universe, if it's set within that world. Maybe they change the power balance among the different factions or characters. For example, if it's a Hogwarts - based fanfiction, how do the teachers and other students react to Harry having such an army?
Perhaps there are stories where Harry uses his unique skills, like his quick thinking and courage, to overcome difficult situations in the army. For example, during a simulated battle exercise, he could come up with a brilliant strategy that saves his team. In some fanfictions, Harry might also get involved in special missions, like rescuing hostages or infiltrating enemy lines.