Thanks all.
I don't really like the lilac cardigan with the black dress in 2, nor the cream jacket over the purple dress (10).
My favourites are the cream jacket over the black dress - 3 (cjh - I have worn this with the green shoes and loved it), I think all toppers work with the zebra dress (but prefer it without one) and the olive and lilac over the lilac dress (9 and 11) although I think either the white sneakers, brown sandals or gold sandals would be better than the grey shown (a bit too muted).
Thanks Katerina, cjh and Dee - great feedback!
And thanks Angie - I haven't worn a sheath style for a while, it is a style I have always liked so determined to wear one again, this feels a bit more modern, and possible to style in a casual way.
The lilac wrap cardigan was a spontaneous second hand purchase - I think it works well enough as a back up option over all dresses but would probably only wear it as a "look" over the lilac.
The following scenario is common here - go out to a BBQ or drinks at friends, nice and warm until about 8pm when a topper is needed (hence a light cardigan is handy to be able to throw on).
I am keeping an eye out for another topper too - but it's good to know I am covered!! I also have the three dresses below but I don't wear a topper over the red, the white I think should work with the lilac cardigan or the olive bomber, and the blue floral is nice with a black blazer and black heels in a smart setting - its a bit dressier.