There is a whole array of differences between MCN's and companies like Storyful and Rumble.com (which I'll refer to as a Multi-Video Network or MVN). For the purposes of comparing, I'll speak about Rumble vs an MCN since I know Rumble best (I'm the founder).
MCN's
- They need to manage your entire channel exclusively on YouTube (they will invite you in the network)
- They may get you brand ads
- They give you studio space to film
- They give you roughly 70% (give or take) of all revenue they generate on YouTube.
* Normally MCN's care most about your entire channel of video and your subscribers.
MVN's
- They only claim single videos on YouTube (not your entire channel. You'll receive a 3rd party claim, which DOES NOT hurt your account or equate to a copyright strike. Its just a monetization claim).
- You get roughly 70% of all revenue generated on YouTube (Rumble gives you 90% on YouTube).
- They use content ID to find all copies and give you the revenue generated on copies (Rumble goes further by placing your video on their own channels and sharing 90% as well).
- They distribute your videos to 3rd party platforms, which normally generates more revenue than YouTube. This is the big value factor over an MCN, since we connect your video to MSN, Yahoo, AOL, television, etc. (every company has different distribution partnerships).
* Normally MVN's care about viral or important single video clips. They are not interested in every video you have.
Basically, if you have a kick a** video that's doing really well, you'll make way more going with an MVN. You get more freedom with your channel, more distribution on that single video, and more money. I'd personally use Adsense for your YouTube stuff, and then use an MVN for your best stuff (but of course I'm biased).
Hope that helps!