Websites differ in many ways. They can be built in different CM systems. They can have different aims. And the scope of their complexity can vary greatly.
In addition, the relevance of Search Engine Optimization (SEO) varies greatly in relation to entire sites and single landing pages. And this applies to each language. Then there is the issue relating to length restrictions, e.g. in meta titles and meta descriptions and how you deal with the issue where some languages can be longer – up to 30% longer – compared to English, when perhaps all of the available length is already used?