[Xacual]

It was said in the episode that the teachers were setting up the "net" to keep the IS in the area so that the group could handle it without it running away again. If anything I'd say that's a much more difficult job then you would think, not that disabling the IS isn't also difficult.

Also yeah we have no idea how many of the teachers have personal IS if anyone of them do beyond like Maya having a mass produced one. It seems like the special ones like Cecilia, Laura and Rin have are saved for representatives or candidates. I'd also assume the only reason Cecilia and Rin have them is because they are at IS academy where the governments sponsoring them would get a lot of data from all the tests and stuff.