MVC design issue

My current project is getting larger and I’m trying to keep everything broken up into functional classes
With the views this is simple, eg; if its a referenced operation symbol, it gets its own class
However with the data/document/model its a bit more complex with options abounding.
Case in point I have 5 mini data models within my model
Should I

  1. Keep this as 1 hugh class
  2. Make it 5 sibling classes
  3. Make it have a parent model class with 5 children ?
    .
    I can see advantages of each of these, and I’m inclined to go with option 3 as that appears to offer flexibility and easier to be extended.
    Am I right ?