No, we don't know. You are making an assumption based on what we haven't seen. In the past teams always played man to man against the patriots because of Brady. With Cam, that may not be wise. Our wrs may be able to have more success aga8nst zone. Let's see what it looks like before making judgements.Their WRs minus Edelman had 40 something career catches going into the opening game.
Sure Cam can perhaps work better than Brady with this group. Sure they can improve. But as it stands currently they need at least one more solid veteran to balance this out.
There's no guarantee on Edelman either. Even the most optimistic fan has to acknowledge the weakness.