Not comparable? Your right, the training is better today, they play on billiard tables today compared to the mud bath pitches of the 70s. Back then the real 'hard men' of the game plied their trade, tackles from behind from the likes of Norman'bite yer legs' hunter, 'chopper' Harris, Tommy smith, to name just a few. Defenders had to face the likes of joe Jordan who would give as good as he got.
Watch any match from the 70s and marvel at the tackles that didn't warrant a card! You'd be gob smacked.
Watch the Leeds United v Liverpool charity shield game from 74!!
The players would finish the match have ten pints and be back out on the pitch midweek with not a hint of 'rotation'