Non-native English speaker. But isn't easier to understand like so,
"Tantivity to Toshi, is as Lucene to Elasticsearch"
"Tantivity to Toshi, is as Lucene to Elasticsearch"
It might have to do with the use of Analogy questions in the SAT (a standardized test all but required for high school students wanting to attend good colleges in America), though it looks like they've been removed?[0].
"_____ is to ___ as ____ is to ______" was the verbatim format of those test questions.
[0]: https://blog.prepscholar.com/sat-analogies-and-comparisons-w...