Earlier quoted context omitted.
> The first vowel and third consonant are different in both dialects. To my eye, each word has no more than two consonants in RP?
To your ear you mean? Yes, both dialects are non-rhotic. I mean the third orthographically.
I don't see more difficulty in saying "ar" is the first vowel in "parker" than in saying "th" is the second consonant in "wither"...