The towed array has much greater capabilities than that.
But, I suspect you already know this...
Yea that's the most accurate and likely the quickest. Three - four ships were getting pinging in the same general area. I think they'll have some wreckage located in a few days and maybe a box.
What people don't get is on land planes can fly for days in a search pattern looking for down craft on land in dense terrain without black boxes. In this circumstances they have a signal they have to locate first by no means easy & no fast practical means of a visual confirmation. It takes time, lots of skill, and luck. Satellites, radar, and sonar aren't magical wands. Neither are tracking transponders.