Play 2 anyways. I would recommend though that you probably consider pulling up a guide as soon as you get the boat. 2 is known as being the most hardest Dragon Quest, and not necessarily for all the right reasons.
I also agree that 5 is better when playing 4 first, but I don't think it's AS necessary as playing 1 then 3. Zenithia is really a small portion of the the 4-5-6 grouping, even if it is called the Zenithia series.
But I absolutely agree, people should start on 1, 4, or 8, with 11 being a maybe.
