In Jan's home there have been several residents who have been problems, though not by virtue of being aggressive - unless pushed by circumstance [in their view].
We have one at present, a big man with FTD, who wanders constantly, trying to get out. He is prone to trying to pull the more immobile residents out of - or off - their seats by whatever limb that is handy. The carers think that, being constantly in motion himself, he wants company.
The thing that is done is that all staff - and visitors -maintain a constant watch on him, and he is moved on when he approaches any vulnerable person too closely.
He has come close to a couple of stand-up fights with a Geordie resident, and they, in particular, are kept apart. Both are deteriorating, so the problem will resolve itself in time.
The other option, medication, is kept as a last resort.
My main concern in these situations, is for the advanced dementia residents, who have no defence.