Nice!

Is it just the launcher or is it also in other parts? Like in games. Try Smart Launcher or one of the many other launchers to see if it fixes it https://play.google.com/store/apps/details?id=ginlemon.flowerfree

Should be something like the system that torrents use: each instance provides the video at the same time to the same user. Some instance give 100kb/s and another 900 kb/s. In the end, the user streams the video with 1000kb/s