ElasticSearch - Isomorphic Type

I am planning to introduce ElasticSearch as our default search engine, and one of the thoughts that came is how best to design elastic types (schema), we may have thousands of fields to index so I came across this article that provides isomorphic design approach using elasticsearch nested type to flatten data and store in form of key and value pair, which sounds pretty generic framework and can accomodate any types of documents. There is a good example of filter and query mentioned in the article.

Article Link - https://orchestrate.io/blog/2014/09/30/improved-elasticsearch-indexing/

I am still getting my arms around ElasticSearch so was wondering how to do sort or aggregration with this approach.

Any help in this regard is appreciated.