Many of who

Hello everyone. I have a question.

Regarding the following sentence:

While volunteers from the foundation patrol the park, looking out for people who aren't following the rules, the increase in tourists, many who come only for the deer, has already led to complaints about bites.

I think that the clause "many who come only for the deer" is a non-restrictive relative clause, which modifies the antecedent "tourists." To be honest, I'd believed that we should say "many of whom come only for the deer" in a case like this. What is your take on this problem?