Order of models in list - Query Precedence?

Kind of an observation, but kinda a question.
The order of models is important if one model uses a field from another.(?)

I have a queue/detail screen. I want the queue to filter based on running user information.
So I have a RunningUser model which pulls in the fields I want, and to keep it out of the way, I had it at the bottom of the Models list.

So I modified the queue model condition to use a field on RunningUser, but it never worked.

until… I moved RunningUser to the top of the model list. (Being able to re-order the models, kinda tells me that it’s important)

So the order of models is important.(!)

Is this the way it’s supposed to work?  I looked around but my queries failed to find any documentation of this. (granted I just queried the conversations and did a quick look at the model tutorial)

Thanks