The other sniper in pvp mode, are they real online players or just mods?

They are just mods. If you turn your Internet connection OFF, even once the start of the session, the session will continue normally, so they can't be for real time playing.

They are just mods, if you turn your Internet connection OFF, even once the start of the session, the session will continue normally, can't be for real time playing

I also noted this. Once I did interrupt the game, went to desktop, locked the phone, and went with my everyday tasks. Hours later I resumed the game at the exact point where I left it. the clock did not advance at all... of course this phenomenon can't occur at real online playing with real players