Which school is better in terms of the international community?
What would “better” mean?
Brandeis, with only about 20% more undergrads than Wesleyan, enrolls about 2x as many undergraduate internationals as Wesleyan does. But I don’t know if “more” is “better”. Are you looking for good Chinese/Japanese/Indian restaurants and grocery stores? A certain faith community (Catholic/Jewish/Muslim/other) that welcomes and supports international students? If you can be more specific about what you want, you may want to inquire on each school’s forum.