People that play with invited friends will trade honor for sure, and since they keep playing, the honor will be replenished. And no one will be able to report or punish them becauyse they wont say in team chat "hey man give me honor after the match", the deal will already be set before game begins.
Meaning the more you play with friends, the more honor you will have, i think the system is broken.
Unless you can't honor people in your group, only those you met randomly in queue. If this happens then the system will be good. Otherwise i don't see need for a honor system which you can reward your friends. Smurfs will abuse this for sure if it can be used in group.
And you can't honor the same person over and over and over. This system is kinda ripped off off DOTA2, where you can give "honor" to your friends too but only once, there is no such thing like "I'm giving the -helpful- honor today and -teamwork- tomorrow" you just can't.