While it is definitely doable, I am almost 100% certain you will regret not just playing 6 accounts as soon as possible.
When I first started out I was also relying on mercs, and it was mainly down to a strange kind of fear/anxiety and feeling overwhelmed by all the possibilities of this wonderful software -- I 100% regret not just going straight to 6 accounts. Truthfully; you don't need a perfect understanding of each class, EQ, redguides or whatever to start playing a full group, just take a bunch of tiny steps and enjoy the journey! You don't need to write complicated inis, luas or macros to have some kind of perfectly optimized play from day 1. Even if the learning curve might seem slightly steeper, the reward long term is substantially higher!