I disagree, Ottow could not do shit on the ground, he even gassed on top while attacking. Not poor ground game, it was a solid defense. Not world class either, but solid. Keep in mind, Northcutt was rocked before the first takedown.
Ottow could probsbly have won standing up. He thought he could beat Northcutt easy on the ground with a wrestling background, big mistake.
Superior cardio is also a skill. Paired with decent explosiveness I get the impression Northcut is gaining momentum. He simply needs more experience, but cardio and power wise he is already at elite level.
His chin is still his weakness, sticking it out as a huge target and keeping the left low, inviting timed counter attacks as seen in the first connect. This is an issue. He is lacking a proper defense and dodging standing up, every time he attacks he is pretty vulnerable for a counter.
Other than that, with a few more fights and with that conditioning I see him fighting for a title after 3-4 more wins.