FWIW, Hawthorn currently have two International Category B rookies on their list and recently upgraded another. In that sense, they're experimenting more than us.
They have Kurt Heatherley and Shem Taputu from NZ, as well as Connor Glass from Ireland. In the context of overall department expenditure, salary cap and list placings, category B rookies are a low risk, high potential candidates. Most of them end up as busts, but it's a great alternative avenue to find new talent outside of the U18 system and state leagues.
I think Cox will make it but I would be surprised if he plays more than 1-2 AFL games in 2016. That would either be really good or really bad news.