Yeah this antagonist is a little on the cunning side. He's also the first true villain Bakuman has.
Bakuman 3 Episode 8
The sad truth in a popular magazine like Jump, is that writer's popularity changes drastically with the editors. They may not like to admit it, but each editor secretly hopes for the next Toriyama or Oda to walk in and show him a masterpiece or even one in the making.
Nanamine is a calculating devil who purposefully exploits that flaw. He knows how to wow the editorial department and make them take notice. After he's done that he self promotes and lucks out with the editor-in-chief reading his chapter and giving it a seal of approval.
In a way he's the anti-Ashirogi Muto. He hasn't struggled, it takes him only a little bit to get a one-shot commissioned and approved and at the end he's gloating to the duo that inspired him. Not a bad villain at all! Unfortunately for him. using the internet cannot be without hiccups.
What the episode does touch up on in terms of real life manga industry issues is the age-old content over quality paradigm. Often a magazine may reject a manga not because it's not good, but because it doesn't have what the magazine looks for. Shonen Jump has built a reputation on running action, adventure, sports and many other series that glorify friendship and camaraderie. Mashiro even points out how Nanamine's work doesn't have any of that.
Proof of this undeniably exists. I recently found out Shingeki no Kyojin was first submitted to Shonen Jump but was rejected. The reason was simple: it didn't fit the style Shonen Jump uses. Now the manga is a huge seller with an upcoming anime, but before that it was turned away from a major publisher.
Final Note: The manga sequence - beginning of the episode - went on for a while. A little too long if you ask me.