Network effects: Tunisia is quite close to Europe.
Visa Access: It's limited but still https://en.wikipedia.org/wiki/Tunisian_diaspora vs https://en.wikipedia.org/wiki/Overseas_Chinese. Relative to population size, Tunisians moved more overseas.
Geographically close to Europe but I bet Europeans/Americans do not feel that way. Again due to various factors.
VISA: For Asians there is one advantage - they have some established characteristics - like hardworking, reputation in IT etc. Again not to say others do not have it but when people talk about IT guy/girl they refer to Indians or Asians - NOT Tunisians.