At my place, leaf-cutter bees prefer a hole size of 3/16", but will occupy larger and smaller holes. The instructions I read
online for mason bees recommend a hole size of 5/16". That's within the size range that the leaf-cutter bees will use, but they only use them after smaller holes have been filled. If I were to attempt to cultivate mason bees, I would cultivate them separately, at least to start. At my place leaf cutter bees are active in late summer.
I think I've only been stung once by a leaf-cutter. I don't know if I'd call leaf-cutter bees non-aggressive. Maybe it's just the honeybee keeper in me being hyper-wary. When a bee starts making threatening sounds, and I'm not fully protected, I'm running away regardless of species.