I'd never really thought of it like that
You're right that Ross rarely plays the ball in behind the defence and Rom is always looking for that ball
Hmmmmmmm
That's why everything breaks down in attack. You have a playmaker who wants to get the team up the field by making it stick in the final third, but a striker who has no interest in that and wants to spin the last man and grab goals.
It's a toss up as to what you prefer, but we've never played to either players strength consistently.
My view is that people seriously overrate Lukaku and underrate Barkley. For example, people criticise Barkley for holding the ball too long; yet if you look
off the ball when he has it there's absolutely nobody showing for the ball to feet, basically ever. So he eventually turns round, looks to start again and can be dispossessed on occasion.
Yet there's still an intelligence and thought to what he's doing. I can't remember the game, but he was on the right touchline and held the ball instead of releasing it, and there was a groan around the entire ground. Then he strung together about six passes across the pitch and set up a beautiful goal, shutting everyone up.
Top sides play with that possession football in mind - looking to prod and probe, find gaps, utilise clever movement to drag players out of position. Barkley is made for that; Lukaku really isn't. And that's not just me saying it - Meulensteen, Redknapp and numerous others have seen the exact same flaws and pointed out that top clubs can't tolerate the risk Lukaku is.