On matters of strategy against a large competitor the easiest is to seize untended positions. In competitive industries there are few but they can be found by figuring out what current customers disdain and love.
Once a market is found. See where everyone stands and where everyone tries to be. See what they are neglecting.
By doing so you can take the neglected and become positioned where others are not tending. Be wary of following everyone else. Search for a market with a small very well defined group. A small group. That needs are not being tended and serve.
This is how one secures a foothold into arenas where titans work. Seize untended positions and keep your ear to a small niche and work from there.