Yes, but I'd rather it be controlled by the AI than an active player, personally.
Trust me, I am not underestimating the AI, after all my war with Portugal was rather costly, but I know it's less... deceitful than an actual player, and it won't be able to use diplomacy to its advantage as much as a player would, so it's more vulnerable as it is.
Of course, such an invasion won't be easy, that is why we must plan it in advance.