What makes a world-class university?

According to Times Higher Education, a world-class university, one that is in the top 200 of the THE World University Rankings:

• has a lot of money
• has a lot of money for research
• has a lot of staff compared to students
• attracts staff and students from abroad
• collaborates with international researchers.

All of these data are derived from the Thomson Reuters InCites programme and they are all indicators in THE world rankings.

The article compares the top 200 to the top 400 universities. It seems at the top that money talks loudly, but internationalisation has a limited impact -- 20 percent of staff from abroad in the top 200 compared to 18 percent in the top 400, 43 percent of papers with international collaborators compared to 42 percent.

What isn't there anything about citations and research impact. Wasn't that supposed to the rankings' flagship indicator?