basically it all relay on to increase IELTS score... my husband and i worked hard to give it our best... husband's IELTS is CLB 10 on all bands. This is the main boost of all.
İ have to say we are unlucy on age point cos' we both are 40

My husband's phD helped a lot. And lastly with sibling point there comes magic 440...
Wish you all the best, I believe with CRS 423 you have fair chance.. just be patience, be positive..
if you can increase IELTS go for it...