It splits the power between the whole stream.
Let's say for the sake of argument, I was HOC. Under the old system I could appoint a bunch of friends from other streams that don't ever show up on Imgflip presidents stream. Then if I decide to be an asshole, I can do whatevers I want with the stream. A law banning Democrats? Why not? A law banning gerbils because I only like furrets? Absolutely! A law banning anti anime memes? Who's gonna stop me?
Under the new system, we end up with around half the stream in the Congress or Senate. So a majority of the stream gets a vote. Now if I wanna pass a crazy bill, I gotta meme chat 20 people and somehow convince everyone to ban gerbil memes.