Hey Chao,
Glad to hear from you. Yes, they could be. You can import 33 EAs in one Portfolio Expert Advisor and for the 3 currencies you would have 3 different Trading Portfolio Expert Advisors.
You can do this my importing back all the EAs in the Validator of EA Studio, and than place them in Portfolios. After that just export the Trading Portfolio Expert Advisors.
Kind regards,
Petko A