Harry Kane and Jimmy Greaves really are from different eras (not just the 50 or so years) in so many ways - the whole area of training is hugely changed with trained being something that takes up a full day for Kane on 'no match' days, whereas for Greaves and co training was very much a couple of hours, with afternoons dedicated to golf, days in pubs or whatever and at half time in a match Greaves would be known to have a swift half or pint and a fag - unthinkable to today's generation.
And if you go back 50 or 60 years before Greaves, Spurs star striker was Vivian Woodward, - 61 goals in 131 league games (about 1 in 2) and with an England career of 29 goals in 23 matches.....but at that time England caps were only awarded for games against the Home Nations, with games v France, Netherlands and other european sides being played by the England amateur side of for which Woodward played with 57 goals in 44 matches.
Interestingly FIFA recognise most of these amateur games as being full caps, although not the FA, and under FIFA rules Woodward would the be all time highest England goalscorer, not Rooney, but even under the FA rules he was highest ever England goalscorer for almost 50 years after he retired.
Woodward captained Spurs, England and England amateurs as well as a Great Britain side who won the olympics football in 1908 and 1912.
And all that as an amateur, being a full time architect by day so limited time for training and indeed could have played more for Spurs if he had not needed a full time day job to earn money - so he cannot be compared to Greaves due to the level of training he did (or rather didn't do)
Kane is a fantastic player and fantastic goalscorer - and so was Greaves before him and no doubt Woodward before him.
Just from such different eras we really cannot easily compare them.