Those selected do not exactly all seem to fit the stereotype to be protective, from what I have observed of their personalities from their actions or words.

[ His gaze briefly slides on over to Matoba as he says this before he brings it back to Sinclair. ]

But they do seem to at least mostly relatively mature than most. Or, as you have said, are inclined to be protective.

...And as for your question, in this case, I imagine by unnatural means.