Yes, I think you will. My 'Avante-Garde' is blooming now and the flowers are small and reddish. I think they will be lost and if you look closely that they might clash. They are a plum red rather than a brick red. I'm not sure, I sadly, don't have room for any of the ninebarks. I think one of the yellow Tanguticas would be great with your ninebark. 'Huldine' too.

I have 'Juuli' growing over 'Crimson Pygmy' and it is a fabulous combination.

Thank you so much for your sage advice. I'll run 'Avant-Garde' through my huge Viburnum sargentii 'Susquehanna', and move my tangutica, which is not in a very good spot' to the 'Diablo'.