Yes, that's a good general ranking! Here’s a breakdown of the intensity in common usage:
Yummy – Usually casual and child-friendly, indicating something tastes nice but not necessarily gourmet-level.
Tasty – More versatile, suggesting good flavor and enjoyment but without extreme enthusiasm.
Delicious – Strongest of the three, conveying something very flavorful and enjoyable, often with a sense of high satisfaction.
This ranking works well in everyday English, though, of course, the nuances can vary depending on context.