Strictly speaking those statements are indeed different as you've pointed out. The former has additional stipulations in that there must be multiple heuristic s

Strictly speaking those statements are indeed different as you've pointed out. The former has additional stipulations in that there must be multiple heuristic search algorithms used and they need to be organized in some modular fashion. What I believe the commenters were getting at is that those aren't very meaningful limitations. One of the most straightforward implementations of a system where a user can search multiple orthogonal sources of information would be to define separate algorithms in a pluggable modular form. I also imagine most search algorithms could be described as having heuristic components, probably especially those tailored for a particular type of information.