I think it's hard to really compare Lukaku/Barkley to Shearer/Gerrard because despite all having obvious talent only two of them had the apparent leadership qualities to drag their teams through a game. Despite my love for our players we don't have anyone of that ilk in the team currently who can kick their own teammates backsides and get everyone roaring again. Then again Martinez can't either and that's why I think we always struggle for the full 90 minutes if we start slow.
It's not just that we don't have them as such, I think the type of player that grabs games "by the scruff of the neck" is fast fading from the game.
Players are much more introspective and focused on the individual stats by which they live and die these days.