Thank you, all clear now. So if you have 9 players beside you in group you could max gain 9 trophies. If you challange someone and win you get the trophy, untill he revenge you back and gain that trophy back.
And if you play a match you cannot be challanged? So it may be good idea to challange someone in last minute to prevent getting trophies stolen? And if someone challange you, you cannot challange someone else in the same time?