Multi DB for running wp-multisite over 2 servers

I am looking to try to run a single multisite over 2 servers because it consists of some very important sites and some that are less so. If we lose the less important ones for whatever reason,(server goes down, etc....) we have a little more time to recover versus the more important ones. I was looking at the multi - db plugin and even though it isn't supported, it seemed to have a vip feature that I might be able to use. This line is the one that made me curious in the documentation -

Unless you have a blog/site that gets a ton of traffic and you want to put it on another physical server for performance reasons, then it’s not really worth it to bother with this feature.

Is it indeed possible to place one multisite over 2 physical servers using this VIP setting?
Thx