Though I do feel like Frank would be able to understand the complex morality/problematicism of it, because Matt really *didn't* have a choice in killing the people that he has, for the most part--'I'm fourteen and fifteen and sixteen and desperately want to please you and our owner and I've been carefully and ruthlessly trained to be obedient and you're ordering me to, standing right there waiting patiently for me, and god knows what you'd actually do to me if I refused' is not real consent, you know?

Plus he might be more freaked out by what he sees as brokenness. (What Opposite sees as evidence of proper training. They have many differences of opinion.)

And I think Opposite would both deeply resent the situation (fuck this shit! New owners without even a warning! God this is bullshit!) and both be annoyed by and respect Frank (on the one hand, cheap-ass stuff in the safehouse or, omg Opposite in a motel room, THE HILARITY, but on the other, Frank is a) skilled, b) smart and c) actually dangerous enough for Opposite to like him and definitely respect him).

And I would love to see the whole dynamic play out. Depending on if Frank reacts really really badly to Opposite politely offering up his assassin and executioner skills and/or Opposite trying to wake him up with a blowjob, they could really have this whole passive-aggressive conflict going on.