Your examples reflect what I think may have happened--travel under another's papers. Makes me wonder/worry what happened to "Abraham" and where (back in Poland?) because the family's relocation to England happened in response to pogroms.
I knew they were same name and highly unlikely for brothers alive at same time, which is why I posed this dilemma here.
Yes, thought of cousins, but the survivors who knew relevant folks say they weren't cousins, but their childen were.
Definitely two people, and I agree, some story to be told, if only . . .
Thank you for your ideas. Yes, gravestone has "Abram Moishe" (because only placed recently, by descendants who've heard same details).
Thank you all for your thghtful feedback.