S
You clearly have absolutely no idea how merle works, and are pulling baseless theories out of your undesirables to support your uneducated opinion.
This is my opinion: merle to merle breedings can be done haphazardly, with high white content dogs who are not tested in any way, or they can be done responsibly with low white content dogs who have been health & dna tested. Imo, we see so many deaf and blind Aussies because they are bred by BYBs and show breeders alike to be "flashy", with as much white as possible.