User blog comment:SayuriDarling/The Mark of Athena Official Discussion/@comment-4649443-20121014204738/@comment-5577244-20121015165449

As to your first question...

The Romans and Greeks were radically different cultures. What was important to one may not have been as significant to the other, for example Janus the Roman god is god of doorways and choices and begginings, and to me seems to resemble Nemesis, the Greek goddess (all greek according to Riordan because she never really changed when translating to Roman) of revenge and balance. Technically they are patrons of different things but sort of the same. The romans had alot of gods already before assimilating Greek culture such as Tiberus and Romulus (sort of...). Alot of mythology can be changed or "edited" as science progresses in a culture. Its happening today with the whole religion vs science debate.

And for your second question...

I think Riordan ment for this series to be focused more on the Romans than the Greeks and COULD be why Percy and Annabeth fell to Tarturus at the end of MoA. Of course hes going to rescue them eventually (Or I will find him and we'll have a little "talk" about his treatment of my favorite charecters...) but now this give him a chance to focus on the new charecters, Specifically the Romans because they now outnumber the the Greeks 3-2. Also this is the perfect chance for Jason to step out into the leading role and ACTUALLY develop a distinctive personality. Right now I feel like I dont know him enough to be emotionally attached because hes such an archetype!

Hope this helped clear some of your questions up