Are they our superiors in the invasion, then? And are there any more instructors aboard?

I suppose Father Gregoroth is who taught marksmanship as well, despite him seeming to disfavor it? I like the idea he wasn't particularly fond of Ilya since, although he went through with the normal melee training, Ilya was probably about a good a shot as that bruiser when he was first enrolled. 

So far as Father Antonin is concerned, I Father Ilya has only respect for the man's abilities and legacy... Yet is utterly uninterested in learning to heal. Or his habit of doting on students. As such, no lost love (though none of this translates to any level of dislike, mind you.)