If one believes grammars to be prescriptive, rather than descriptive, we can come up with all sorts of illogical and silly rules.

I suggest deploying functional/situational markers as usage guidelines: eg. communicating respect and formality, versus casual and informal. Word order matters as much as case. We might say/write "Help Walter and I compile a list." Or, we might say/write "Help me and Walter compile a list." Both sound "right" depending on the context. No need to get your/our knickers in a twist.