It's more like how things work in American sport. So beyond being too long it'll be confusing as well.The reason this won't work here is, because you are not just playing games within your own groups. That is something we see in other ICC tournaments. But in IPL, you play two matches per team inside your own group. Then you play 2 matches against one team from another group. And finally 1 match with leftover terms of another group.
So you are playing all the other teams and not just teams in your own group. That is why the top 4 out of 10 for playoffs instead of top 2 from 5.