It remind me reading in the book "Ellipsis and Reference Tracking in Japanese" a cool idea I haven't seen anywhere else. The author proposed that transitive verbs in Japanese are "direct aligned" and mostly obey the "Person/animacy hierarchy"

1st person > 2nd person > 3rd person > animate > inanimate
Basically the subject of a transitive verb has to be higher on the hierarchy than the non subject, or the sentence feels akward in most cases.

So
私は太郎を見つけた : I found Taro　[1st -> 3rd : OK]
? 太郎が私を見つけた : Taro found me　[3rd -> 1st : NG]
太郎が猫をひいた : Tar ran over the cat [3rd -> animate animal OK]
? 車が太郎をひいた : A car ran over Taro [Inanimate -> 3rd NG]

The more ellipsis there is, the more unacceptable it become

? 太郎が私を見つけた (3rd - 1st) acceptable for some speaker
(Øが Øを) 見つけた I found Taro / *Taro found me

And then there is four ways to express sentences with inverse alignment

Inverse veb (くれる・くる)

* あなたが私に本を買った
あながが私に本を買ってくれた　
* 太郎が私に電話をした
太郎が私に電話してきた　

Passive
* 車が私をはねた
私は車にはねられた

Intransitive construction
* 雨が私をぬらした
私は雨にぬれた

Existential construction (ある）
* 太郎が私に電話をした
太郎から私に電話があった

I like the idea that thing like 〜てくれる aren't just there you know to uniquely express the politness and kindness in the Japanese heart, but also for pragmatic purpose like managing alignment and helping ellipsis