To compare Kane with Benteke is like comparing Sammy Morgan with Andy Gray. Like comparing Ricky Lambert with Diego Costa. Bobby Zamora with Stan Collymore. Benteke is an amazing footballer not applying himself to the task Kane is an average footballer applying himself amazingly to the task at the moment.
'Zero doubt'? Benteke was playing in Belgium when he was 21. Had he not been, who knows how he would have compared. And before anyone says 'well, if he were that good he wouldn't still have been in Belgium', who's to say that if Kane were Belgian he'd have played well enough to leave there yet? It's all very speculative.