When talking about verbs of giving/receiving, textbooks tent do talk about only the relation between 1st person and the other persons (i.e. くれる 2/3→1, あげる 1→2/3, もらう 1←2/3), and let learners generalize the rule to the other cases.
According to my grammar book, when talking about receiving of a 3rd person character from another 3rd person character, the speaker should regard one of them as the 1st person and apply the rule of [もらう 1←2/3]. What I have understood is, the speaker needs to take the more familiar one as the 1st person and let the other the 3rd.
Then I am confused when I do a multiple choice from JLPT N1 (2012.7):
In this case, I want to express the receiving of Ishida (2nd) from my brother (3rd). The suffix やってください is alright to me, but how can Ishida morau something from my brother, if my brother is more familiar to me than Ishida? My grammar book says, if a reception doesn't affect the speaker at all, the more neutral 受け取る should be used. Here if I don't consider やってください, when just talking about the reception, is もらう grammatically/semantically legal (e.g. a plain narration, あなたは私の弟からギターをもらった)?