In reply to VerifEx:
I would look for standard interfaces between blocks (for example, APB, APB, etc.). This makes it easy to interface with these blocks by re-using existing UVCs.
I would also look for how well blocks are documented. If there isn’t much investment in documentation, what might be the case is that later in the project there may be a decision to change the blocks around (move stuff from one to the other), which will negatively impact your verification.