Help with Access Rules

I find Grist access rules very very complicated. I always suffer with the logic to implement them.

I have a table for COMPANIES. Each COMPANY will have a user associated to it.

I have two options… someone creates the company and select a user from an user table (user and email).

OR let the user create the company. And user name would be recorded in the column that identifies record creator.

How I proceed from here?

edit:

I decided to create at the Company Table a email column.
The document Owner creates the company, by writing Company name and email that matches the invited user.

These are the access rules. So, at the EMPRESA table (Company), I am saying user that matches the email of the row should be able to see that row.

But it actually can´t even see the table. Unless I set rules for users that are different than owners to be able to see the table. But then the user can see ALL companies, not only his.