multi-domains or share models

Hello! I am creating three applications with different domains would need to share the same template rules.

In domain-a.com I have an advertising platform

In domain-b.com l have a portal

In domain-c.com I have an processing internal application

I thought about getting them on the same server, but I could not imagine that the server could direct the domain to an specific module of Yii application.

So I thought just make them share the models, since three servers are on the local network. So could have a new server to only shared models.

Some of the two possibilities is possible?

I chose to use different domains and applications, maintaining control through a structure structured in the repository, where models are above the folders of applications.

The publishing work will be higher, but could not find way to do what wanted otherwise.

If anyone has ideas, I’m always willing to improve!

thank you!