I understand that English and Russian contain the most words
Probably not. The languages with the most words are probably fairly unknown tribal languages spoken by few people. Australian Aboriginal languages for example tend to be far more specific than English, dealing more with particulars than with generalisations. They have fewer generic terms and thousands of specific terms for things or actions. So instead of just using the generic word for 'river' to describe a place, they might have a name for each bend of the river, and words for every kind of relationship, every type of campfire, every object in terms of its sacredness, etc.
