Like life? I'd say probably a mix of both. Good points, there!
I like Aig's complement of Leo's leadership skills.

ahem
They do portray Raph as certainly resenting Leo for being "Splinter, Jr." The lecturing, etc. For Leo for just being
Leo.
And yet, I think Raph is able to look at himself, and finally take responsibility for his own part in their ongoing conflict--in terms ofalso feeling he is inadequate, as you said.
But in the movie, the path he is taking to dealing with his issues, is focusing it toward picking at Leo, being disrespectful to Leo by leaping into battle, smirking at Leo when Splinter's scolding Leo, throwing it in Leo's face he doesn't want to work with Leo, then finally attacking Leo once Leo's "busted" him on the Nightwatcher gig.
And yes, to be fair, Leo's brought Raph to that point, when they get to the second part of their fight on the rooftop. First his 'dissing' of the Nightwatcher. And particularly in saying what he does with the "I'm better than you." It's like, the whole frustration of trying to improve himself for his brothers, and for Raph's treatment of him just finally comes out.
But Raph can't back down and find a solution that involves dialogue to resolve their differences. He lashes out in a fight.
I think you see the inner truth about Raph when Raph actually breaks Leo's swords, and darn near does serious damage to Leo, too--then he has to run off because he can't face the truth of himself at that moment. He isn't gloating at all, isn't laughing, isn't celebrating. He's horrified. Doubly so when he realizes that Leo has been taken, most likely as a result of how Raph left him.
And on the other end, Leo seems rather horrified, too. He's certainly completely shaken up, devastated, because it's like maybe he sees no hope to reconcile with Raph. And then, of course, that means he's failed Splinter's trust in him. And what Leo wanted for himself.
Some can say what they want about the plot? I'd say, even to having to hit a PG rating and having to turn in a movie of only an hour and a half, there are areas of the movie where the plot is very deep if you know the characters.
And when Raph is able to reunite with Leo, there's some interesting stuff there, too....