This will be my 9th Disney cruise, mostly with all adults or adult children and have always started in the Royal Palace (reminds me of a Main Dining Room). When we asked our wait staff if there was a rhyme or reason for the order of progression, he said that Disney tries hard to keep adults together. But, as you pointed out, this must be impossible with the amount of passengers sailing daily, so it must have been a crazy coincidence that we always started there! Thanks for the info about the 4 night cruise!