What is the average size of the documents you are indexing?
What is the average size of a result set you expect to have returned?
How many concurrent queries do you expect to need to support? Do these queries search all or a subset of indices?
Be aware that wildcard queries are the most expensive queries in Elasticsearch so you may need to optimise queries and mappings for optimal performance.
If this thread related to the same use case described in this thread I do recommend that you benchmark and test with real data, queries and workload.