I hate to say it but your problem here is ES itself.
If you just need "Lucene but clustered" I highly suggest looking at Solr instead, it's design is much more straightforward and has pretty much all the most important knobs for actual indexing that ES has.
If however you are tightly coupled to ES API or use it with 3rd party systems you are sort of up shit creek without a paddle...
Ran ES at large scale for many years, eventually gave up and only use Solr or custom built search engines these days.
If you just need "Lucene but clustered" I highly suggest looking at Solr instead, it's design is much more straightforward and has pretty much all the most important knobs for actual indexing that ES has.
If however you are tightly coupled to ES API or use it with 3rd party systems you are sort of up shit creek without a paddle...
Ran ES at large scale for many years, eventually gave up and only use Solr or custom built search engines these days.