There’s a huge difference between a couple of Aurors maintaining a couple of Patronuses (I thought it was Patroni too, but the wiki refers to them as Patronuses) to protect themselves from the fringe effect of the Dementors and trying to hold back over a hundred Dementors actively trying to leave. This is particularly true when you take into account that not only would this effort have to maintained, but Dementors can fly, meaning they’d just float right over the wall of Patronic energy (isn’t coinage fun?).
Maintaining a sphere...I don’t recall, could Patronuses of terrestrial animals fly? If they couldn’t, that would make it even harder to maintain a sphere, since the upper hemisphere would only be maintainable by those with aerial or aquatic Patronuses, given the assumption that water-animal Patronuses would “swim” through the air.
It’s notable that while one Patronus could have theoretically shielded all three card-players, all three aurors had theirs out, implying that they were all needed to combat the proximity to so many Dementors. Additionally, more Dementors means more of their effect seeping through the Patronuses, which sucks away your happiness, which weakens your Patronuses, which means more of their effect...etc. Heck, when the two remaining Dragon Poker-playing Aurors had both of their Patronuses up, all it took was one Dementor coming close to them to break through enough of their Patronic energy to give them instant headaches. Think of how many it would take to stop dozens of them all trying to wear you down.
Sticking them in their own cells and patrolling to make sure they haven’t worn away too much, shifting them to other cells and repairing the cells when they do...that could be possible, especially if magical repairs don’t break down faster around Dementors. It also might be worth it to see if you could Transfigure them into something else, in the hopes that though they’d still be unkillable, they hopefully wouldn’t project the decaying effect when turned into, say, a rock.
There’s a huge difference between a couple of Aurors maintaining a couple of Patronuses (I thought it was Patroni too, but the wiki refers to them as Patronuses) to protect themselves from the fringe effect of the Dementors and trying to hold back over a hundred Dementors actively trying to leave. This is particularly true when you take into account that not only would this effort have to maintained, but Dementors can fly, meaning they’d just float right over the wall of Patronic energy (isn’t coinage fun?).
Maintaining a sphere...I don’t recall, could Patronuses of terrestrial animals fly? If they couldn’t, that would make it even harder to maintain a sphere, since the upper hemisphere would only be maintainable by those with aerial or aquatic Patronuses, given the assumption that water-animal Patronuses would “swim” through the air.
It’s notable that while one Patronus could have theoretically shielded all three card-players, all three aurors had theirs out, implying that they were all needed to combat the proximity to so many Dementors. Additionally, more Dementors means more of their effect seeping through the Patronuses, which sucks away your happiness, which weakens your Patronuses, which means more of their effect...etc. Heck, when the two remaining Dragon Poker-playing Aurors had both of their Patronuses up, all it took was one Dementor coming close to them to break through enough of their Patronic energy to give them instant headaches. Think of how many it would take to stop dozens of them all trying to wear you down.
Sticking them in their own cells and patrolling to make sure they haven’t worn away too much, shifting them to other cells and repairing the cells when they do...that could be possible, especially if magical repairs don’t break down faster around Dementors. It also might be worth it to see if you could Transfigure them into something else, in the hopes that though they’d still be unkillable, they hopefully wouldn’t project the decaying effect when turned into, say, a rock.