Not really. This will make AoE attacks way too powerful, players will be able to rush through monsters, so quests will be way too easy. And targeting will suffer from this too. This might look "cool" at these videos, because he is using Rats as an example. Imagine bigger monsters like Demons. That would look so bad...It's nice to see some good ideas.
I guess this will also fit this project:
Here is a first rough draft of "Creature Stacking" we are making this for many reasons... one of which is so small monsters can "swarm" you. Here is Draft 2 (Works a little better now)otland.net