I would find it odd for half-siblings to be named
Thomas and
Tamsin. Obviously it wouldn’t matter if they were step-siblings or some other non-blood relation that happened to be in the same family.
Like ari said,
Leon and
Leo have different vibes, but if you really liked the letters in that combination
Leo still works/it’s almost the same sound or idea.
Using
Jay to honour a J name is pushing it a bit. It would be more honouring to use a version of the name than to spell out the initial.
**I love God far too much to be religious -
Jean Claude Koven**