Ashley Elizabeth Case has an especially nice flow.
"Flow" is a combination of rhythm (syllable variation), letter sounds and letter placement. Just as in music, everyone hears names a little differently and has different tastes.
There are good flow/bad flow "rules", but they don't apply much of the time and they are more likely to reflect the namer's taste than an absolute truth. Flow "rules" are actually guidelines and they are handy to know.
1. Syllables of combos should be varied. Your example is a good one, having 2-3-1 syllables.
John Mark West with syllables 1-1-1 is choppy but John Charles West with 1-1-1 has a better flow.
So, 1-1-1 does not always need to be avoided although most of the time it won't work.
2. Many people dislike combo names that end in the same sound, and follow this "rule". But if the names have a variety of syllables, they can flow well. Anna Laura - sing songy; Anna Lucia - musical flow.
3. Combos that begin with the same sound are often shunned as non-flowing. Dominic Dylan (bad flow in my opinion). John Jacob, James Jordan, Josiah Jude, are nice to MY ear, but others may cringe. So "flow" is often a personal thing that defies "rules"
4. Some people absolutely must have more syllables in the first name than the second. It doesn't matter to me. The sound of Flow is once again personal taste. Catherine Rose or Rose Catherine both have a nice flow to me.
5. The first name ending with the beginning letter of the middle name. Some people think that it mashes the names together, but others natually pronounce them in a way that this doesn't happen.
Ex: Ethan Niall - I pronounce "Ethaniall" = Bad flow. Aaron Nathaniel flows very well when I say it.
There are so many variables to Flow. Guidelines are helpful, but in the end it's the pleasantness of the sound to your own ear.