Desdemona is a wonderful rose.

https://rightroses.com/desdemona

Claire Austin will likely be a small climber in zone 10.

If your plan is to get PJPII, I would select Charles Darwin, which has the benefit of being close to thornless. PJPII can have a yellow tinge that could play very nicely with Charles Darwin.

I think Emily Bronte and Desdemona would make a lovely combo too!... I think the look would be more harmonious than Charles Darwin and PJPII. To my eye, Charles Darwin and Emily Bronte would make a so-so combo...

Desdemona is very beautiful!

Beginning to think I am of little help... however, my thought is, if it were me, my next planned purchase could help me to decide this one...

Very good suggestions. And very interesting. I have Emily Bronte and Desdemona next to each other as well. :)

Thank you all for your very helpful replies, but do you know if these varities will grow well in partial shade? Thank you.

P.S. I agree that desdemona and Emily Brönte together would look lovely, especially in a bouquet. All those combinations you mention made me fantasize about the fragrance too.