According to watchitallabout, there will be a 40mm version:
Christopher Ward 10th Anniversary Launch – SH21 and C9 5 Day Auto | Watch It All AboutFinally, the C9 5 day auto. Yes, it’s 43mm, but a 40mm version is coming soon. It’s beautiful, just like all the other Harrison watches. And yes it costs £1500, which is a lot. But don’t forget what your paying for. First, the COSC chronometer certification is £100 straight out of that. Then think about the 4 years it has taken to develop this movement. How much more would an equivalent from one of the big Swiss manufacturers cost? Johannes said that the SH21 is made so much better and will last longer. And I believe him as he talked a load of jargon at me to prove it. It went over my head naturally.