A great idea about dealing AFK in rank game

I really have an great opinion about changing the way of dealing AFK in rank .
My reason is below.

1. 4V5 is just too hard to win, so 20 minutes are just wasting 9 players time .
2. the players will have a bad feeling because of that.( especially one who is in promo and lost that game). Even I am the 5 and I got a free win. I will feel bad too.

So the ways to change

1. If someone is disconnected , after 5 minutes (maybe 8 minutes or 10 minutes) he doesn't come back , the team can surrender (vote) even before 20 minutes. 2.The lost side should not lose any point/promo , because that is a 4 V 5. The AFKer should take the responsibility, not that 4. 3.Maybe the win side just can get half points(compare with normal win's points ) for the free win.
2. If one AFKer duo with the other . Both of them will lose the same points(promo). Because the AFKer will just afk on purpose .(like the other is in promo, if he knows they can not win , he can afk then the other will not lose the game)

And , I really do not know what the disadvantage is about this change . It just can make the rank more fair . And I think, all the players will be happy about this. Thank you!