At least they started off roughly with each other.
Iris: Wait you SHOT Barry?
It's just the way it goes.
Barry is very much the Superman of the Arrowverse the bright beacon of hope, Ollie is of course the Batman with his broodyness and tactical thinking and at the end of the day the way Kara's used makes her the Wonderwoman (irony!) as she comes from elsewhere and helps this world to be better.