Fine. I don't see the relevance of GLC sales in the USA to E Class sales in Australia, but if you want to relate them . . . .
Australia sells just over 100 E Class per month. They could offer every single body style - saloon, estate, coupe, convertible, all drive trains - RWD and FWD, all engine types - diesel, petrol, hybrid, and all the different engine sizes in those categories, then all the specification variants of SE, AMG, Premium, Premium Plus etc.
Would it make commercial sense? I think not. That's probably why they don't offer an E Class estate.