Stake weighting, not with network dispersity but with accumulated stakes. Sybil attacks are also not so easy and not even valuable for attackers to apply, and it is no big deal if it really happens.
Please at least read the answer I just replied, I don't want to explain the same stuff repeatedly.
The main idea of the paper was introduced here
https://bitcointalk.org/index.php?topic=5094909.msg49129375#msg49129375.
First of all, thank you for your concern. But you don't have to be offensive because I am not your enemy but a guy who wants to share something and discuss them with someone interested. Maybe I have offended you with some unappropriate words that I didn't noticed, I appologize for that. Anyway, all questions are welcome.
Cumulative stake weighting for branch selection is a good idea, but only when you cannot move a critical amount of stake around on a block by block basis, otherwise history attacks are still possible. This means you need a limit on the amount of stake you can move over a certain number of blocks*.
The 'network dispersity' thing is just nonsense, though.
*) See our discussion with @shunsaitakahashi on PoA -
https://bitcointalk.org/index.php?topic=3913439.0