Depends on your setup, Im running active with an 860MP and its suggested that you run the amps on full. If your head unit isnt top of the line or designed to run active I would probably say that it wouldnt hurt to run both. Ive noticed that most amps/HUs dont block everything, some are better than others.
The crossover slopes add on to each other so it is important to factor that in if you are running multiple. Often it is easiest to just run them off the head unit, such as a high pass for your components. Then turn the amp to full. That signal is then split up by your component's crossover to the mid and tweet.
You will typically want only ~80hz and above reaching your components.
I got some advice on here a few months ago on this topic and the results were very good. you should only pick one crossover and use it because if you use multiple crossovers the slopes will be way off. I had a complaint about the sound with my Kenwood dnx and when i turned my amp and passive crossovers to full and only used my HU crossover the sound got much better. the sound is alot more natural sounding, if that makes sense.