Gary,So you don't compare specs with competitors. I think Apple is generally a little lower on the RAM and try to be more efficient to get more battery life. I've always thought a little more RAM would be more efficient, but I have not idea how much power that really means. My laptop runs way more efficient (appears to be faster) when I have more RAM, I don't notice that the battery runs out faster.
I looked and don't see the 2GB reference on the iPad Pro pages, do you recall where it was?
Gary
Looks like the iPad Pro has 4GB of RAM.
https://www.macrumors.com/2015/09/13/xcode-iphone-6s-2gb-ram-ipad-pro-4gb-ram/