You can make something like:
<token postag_regexp='yes' postag='V.*'/>
<message><suggestion>\2 \1 \3</suggestion>
And then fix the false positives, but I am not sure this is correct, to start with.
I would have written like you did, and the various 'próclise' rules I have seen, always refer to writing the pronoun between the negation particle and the verb.
It may be better to look for a public reference before committing the rule, or add it as a style rule marked as default='off'.
If my understanding of these rules is wrong, I should also review the rules I created, although it may take a while.
PS - Unless you mean to write 'são' as a noun. If "não são' means not sane, you would have to write 'o não são'. But I am just saying that from the top of my head. I believe that is not the intended meaning in this situation.