Pirates of the Caribbean soundtrack is very good, but it's also very similar to Gladiator and The Rock, it's practically a hybrid of the two. Just because the composer works for Hans Zimmer's company doesn't mean he didn't borrow elements from the soundtracks.
Heck, you can ever rip off your own work. Most people do, if you've got a resource that can get your end result with a bit of modification and you can do it without legal or moral repercussions, then do it.
But, if you are thinking of getting Gladiator and PotC soundtracks, get The Rock too, cause it's awesome.
Detty. Professional Expert.
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