The phrase "strongest means" refers to the most powerful or effective way to accomplish something. There are a variety of synonyms that can be used to convey this idea, including "most potent method," "most formidable strategy," "most successful approach," "most efficient technique," and "most dominant tactic." Other terms that may be used to describe the concept of strength and power include "unrivaled," "dominant," "unbeatable," "invincible," and "untouchable." Using synonyms like these can help to vary your language and make your writing more interesting, while also providing more specific nuances and shades of meaning to your words.