You may not want to use Duck Duck Go as your search engine anymore

[Arnox]

If you're talking about "one browser controlled by three", you're mixing your terms. You're talking about the rendering engine, not the browser itself.

The rendering engine might as well be the broswer since it covers 85-90% of its functionality easily. The rest is just fancy window dressing.

 

[Houseman]

The rendering engine might as well be the broswer since it covers 85-90% of its functionality easily. The rest is just fancy window dressing.

Even if your percentages are accurate, the browser is the most important part in this context of security and privacy, since the browser is the the thing that interfaces with you and your file system.