I also really like how the ORVILLE characters are balanced: they are not the perfect action figures of TNG, but they are also not the angst-machines of RIVERDALE or the incompetents on HEROES -- there's a very careful mix of personality traits, so they come off as normal people. Mercer's furious about Kelly's infidelity, but he's also capable of being civil. Gordon is dim-witted and a drinker, but not uniformly incompetent, just at times unreliable. That balance to avoid both extremity and blandness is very difficult and it's a credit to MacFarlane's writing and the actors that they can pull it off.
This is really what makes it work, in my opinion. I really liked your comparison to Brooklyn Nine-Nine because I actually think that's really spot on. I actually had a lot of concerns about that show as I did with the Orville - while I like Andy Samburg more than most, I was worried that he'd be too over the top for the show to work. And while there's a certain amount of that, I feel like the show took Jake's character seriously enough for it to work. Jake is a buffoon, and he's a jokester and a prankster. But, at the same time, he's a great detective, and he knows when to turn off the goofiness and get to work. The other detectives have their quirks, but they do a great job of showing that the team is capable and dedicated to protecting and serving.
The Orville is the same way. Ed and Gordon are jokesters, but Ed has shown himself to be a great captain with a wonderful care for his crew. He's been willing to sacrifice his life for his crew, and he takes great pain to make the right decision. Gordon seems to be a drunk and a goof, but he's also been shown to be an elite pilot who cares about his job. That way, the characters themselves are allowed to be funny in calm times, but the show can have real action sequences where you trust that the ship and the crew are competent.
That way, you're thinking in the back of your head why the Nine-Nine still have jobs or why the Orville hasn't been destroyed. They're great teams that allow themselves the occasional appropriate amount of humor.
Just like real life.