The benchmark module is focused on micro-benchmarks - benchmarking specific features or specific code. These kinds of benchmarks are notoriously difficult to get right in Java, and the benchmark module is built on JMH, in order to make it much easier to get things right.
The module has a built-in random data generator so that you can easily target whatever kind of data you would like - not just text fields but faceting fields or whatever. For text fields, you would generally use something like a zipf distribution from the English word dictionary.
