Is there a 'general rule' on how the DDP works..

[DISbot]

There is not one item on that menu listed as an "entree"; in fact there is no entree listings at all.

If you mean Tokyo Dining:

There are apps, and then soups and salads that fall under the previously stated maybe rule.
Sashimi and Nigiri probably aren’t included as well as the sides of rice.
Then, everything else up to the children’s section is an entree, and the rest you should be able to figure it out.

I think you are stressing and overthinking it. The general rule for entrees is “would this item count as a meal, and is it grouped with other things that count as a meal?” If yes, it is probably an entree and unless it is disproportionately more expensive ($150 with $50 entrees), or says “for two” it should be covered by a single credit completely.