With the performance figures and price they are suggesting, growing the actual market can move that marketshare number quickly. Another consideration for mGPU is the explicit nature of DX12/Vulkan. Instead of doing physics asynchronously at the suggested prices you could have an entirely separate GPU accelerating parts of a game. It wouldn't be ideal, but two disparate adapters accelerating different parts should provide a performance edge. We still don't seem to have seem the fastest Polaris 10 variants either and it seems increasingly likely mGPU setups will come as well given those cooler designs. I can't imagine someone designed a water cooler for a $200 part that can't use over 150W. Or that they are designed to replace the water cooler on an already $1500 card(Pro Duo) that is already water cooled.