"They see us."
Translation:Elas nos veem.
Would the pronoun [nos] be in the same position in the sentence in European Portuguese?
Yes. Not probably, it's the only accepted form. At least in the Present Tense. If it were the Subjunctive, the pronoun comes before the verb (se / que / quando NOS vissem / vejam / virem). Mind the accent, by the way.
You'll be understood, but it'll sound very weird, and it's not correct. "Elas nos veem" would sound too formal too. You'll most likely hear "elas veem a gente", actually.