Ok so Optimus reason with the Dinobot that they should join force with the Autobot or they will die by the hand of the creator. He convince them that only together, they can survive against the creator but then he ride them into the battle against Galvatron??? Who doesn't have anything to do with Quintesson and he didn't even need their help while he was against Lockdown- The creators's right hand man. And then, in the end he didn't even need their help to find Quintesson too So in the end, his reasoning make no sense at all
I take it as it shows they can trust each other and rely on each other! So when shit goes down on earth, the Dinobots will help without being tamed again.
His reasoning makes perfect sense; the city is threatened, there may well be more bad guys on the way, his friends are in trouble and thus he needs reinforcements, ergo he releases these powerful warriors and informs them of a grave threat. He tries to invoke the old 'we have a common enemy, let's team up before we get fucked up' routine so as to convince the Dinobots that they'll be better served allying with these midgets. Optimus wasn't really caring about specifics; he just needed these giant badasses to help him save the day and that was that.
Optimus needed the Dinobots to help him against all those vehicons. With the Dinobots distracting the vehicons, Optimus had an advantage to take down Lockdown
i believe optimus rode into battle to save bumblebee, hound, & the yaegers primarily...as it was portrayed, they don't win that fight without the dinobots
