I don’t know why you think it’s not possible (or that it’s anything more than trivial). Revenue, affiliated companies, third party service providers, etc are all basic legal concepts.
The risk is far more likely to be inadvertently making the licence overly narrow and preventing usage by companies that you would actually intend to allow (or at least contemplate should be allowed).
Regardless, the text doesn’t really matter. Most companies will run for the hills as soon as they see anything remotely like the contemplated licence. It’s just not worth the risk for them.
shrug The Unreal engine mentioned elsewhere in this threat also seems very simple (an order of magnitude more straightforward as what we're talking about here I'd argue), yet if you go on the Id forums you'll find many questions from people in various edge cases that fall under one category in spirit and another in the letter of the license. But hey, I'm just some guy on the internet, what do I know, we'll just have to agree to disagree until someone really tries to find out.
The risk is far more likely to be inadvertently making the licence overly narrow and preventing usage by companies that you would actually intend to allow (or at least contemplate should be allowed).
Regardless, the text doesn’t really matter. Most companies will run for the hills as soon as they see anything remotely like the contemplated licence. It’s just not worth the risk for them.
Source: former lawyer.