So basically the Kelvin/Narada scene being rammed down our throats is a needless "fly on the wind shield" moment for the sheer hell of "Kewl" CGI battles. Nice...
Yes...you sure figured it all out.
Anyway, we are just speculating here.
None of this is 100% certain or in context with everything that really happens in the movie before,during or after the Kelvin/Narada face-off.
From what I've come to discern in recent months, the Kelvin and Captain Robau/George Kirk are simply in the wrong place at the wrong time when Nero and the Narada emerge from the time rift into the year 2233. They end up as target practice...the first Federation vessel Nero lays his eyes on after getting to the 23rd century.