Unfortunately that's the onto way to go around it but you can do with two employees and not four but that would change the visa you would be able to get with this layout we all suffering under this rules but this the o to legally way to do it
To clarify what I mean by that is as a freelance you will need to have your own company so you can sign a contract with each company you work with as an consultant when you do work for them either that or they will have to hire you on full time and take care of all the paperwork for you and work permit
Yes you can set up an company and then as mention Bill Them for being advisor for them but now you will need office Thai staff and etc an minimum capital of 2million in the company it's a long process and if you do go true all this when you in the end get the company set up and work permit then you will have to add teh location of the other company in your work permit as well