Of course you can! He is thinking about running tren and deca together since the line of thought is you do not want to run two Nandrolones together.... but I still known people that do - go figure.
Please read up on why you should not run two nandro's together.
my opinion:
Test, Eq, and tren is okay choice for compounds to run but I wouldn't really pair eq with tren. To me a better combo might be Test, Eq and Npp. Just my opinion though