Hello again!
I have seen the document where are suggested for the brginners the possible combinations of investigator's decks using only one core set... same thing for the dunwich legacy... but there is not a document that make the same thing mixing the core set and Dunwich together... or is there?
If you mean combining investigators from different boxes, there isn't.
Although you should be able to cross some of them over without much trouble. Part of why the Dunwich "starters" each only draw on a single off class even though they aren't limited to one is so they're less likely to have card conflicts in shared classes.
While there are recommended combinations the primary reason these are provided is to help you handle multiple decks with minimal card pool. The game intends you to pick up any characters and play them together with custom deck building. If you have the core set and Dunwich you should have enough cards to pick 2-3 investigators and not overlap cardpool between them.
If it helps, there are a ton of deck designs here.
Ok, thank you all