I
"I don’t think Shanks is one to have his boys deal with someone directly challenging him"
Not so sure about that.
back on track if it was shanks who took his arm, kid would say red hair shanks not in a battle with the red hair pirates. If I lost to kaido , I will say I lost to kaido, not in a battle with the beast pirates. Kid then went to another yonko's territory and didnt get to see mama either. Its simple, he was reckless, it got the attention of certain members of the red hair pirates and they dealt with it.
This was before he even fought a commander with in wci. Shanks does not need to step in when fodder is involved.

Not so sure about that.
back on track if it was shanks who took his arm, kid would say red hair shanks not in a battle with the red hair pirates. If I lost to kaido , I will say I lost to kaido, not in a battle with the beast pirates. Kid then went to another yonko's territory and didnt get to see mama either. Its simple, he was reckless, it got the attention of certain members of the red hair pirates and they dealt with it.

This was before he even fought a commander with in wci. Shanks does not need to step in when fodder is involved.
Also I dont get "someone cut his arm" who says it gotta be a cut?
He lost his arm in a battle with RHP
Either he lost by overdosing his arm and many people ganged up on him
Or Someone with powerful haki and power blew his arm off