I have a similar style on an excel spreadsheet. Going downwards, I have the sound (phoneme) the name starts in. Going across, I have the sound the name ends in.
It doesn’t matter about the grapheme (letter) so, for example, [name_f]Pheobe[/name_f] and [name_u]Florence[/name_u] both start with /F/.
It is quite a fun way to see how names relate to each other.
I’ve replied to your other topic, but I thought I’d share incase you wanted to try something similar.