To a certain degree yes, the systems they wind up in compete against each other, and since the performance and efficiency is one of the main selling points.
There was serious realisation internally at ARM when Nuvia was acquired that maybe the best ARM CPU designers aren't at ARM anymore ;)
That does not bode well for ARM's overall revenues or engineering teams. The real talent got fed up and went to Apple or various other companies a long time ago, what is left is a highly political company with terrible amounts of dead wood that have worked their way into key positions and able to alienate anything they see as a threat with their pettiness. The only saving grace is they manage to use naive graduates for a few years before they realise what is up and leave for greener pastures.