The Ramban on Devarim 7:6 says:
בך בחר ה' אלהיך להיות לו לעם סגלה שאין לך קצין שוטר ומושל בכל מלאכי מעלה אבל אתה סגולת ה' תחת ידו ולכך לא תטעה לעבוד ע"ז מאלהי העמים וכבר הזכרתי זה פעמים רבות
Loosely translated:
because G-d chose you to be his treasured nation since you have no ruling officer, enforcer, or ruler among the angels. You are directly under G-d's control. Therefore don't stray and worship the idols of the other nations. I already mentioned this many times. 1
The Ramban seems to be talking about the idea that since the Jews, unlike the other nations, do not have a "patron angel". Instead, G-d himself directly rules the Jewish Nation. (as the Ramban says in Devarim 4:15) Therefore, we must only serve G-d, and not turn to idol worship.
There are some opinions that non-Jews are allowed to believe in Shituf (partnership, i.e. that there are other forces in addition to G-d who have influence over the world (see here for a discussion of this)).
Based on my understanding of the Ramban, does the Ramban then hold that the other nations may believe in Shituf, since they do have a "ruling officer, enforcer, or ruler among the angels"?
If the Ramban himself does not hold this view, are there other opinions to that use this logic to explain why non-Jews may believe in Shituf?
1 I don't know where else the Ramban has mentioned this, so perhaps he goes into this in more detail in other places, and answers my questions.