Kane is a great striker and I've backed him ever since he exploded, but he doesn't come to close to matching Sturridge on a goalscoring level. The merits of their games otherwise can be long debated but when it comes to pure goalscoring, Sturridge in his three semi-fit seasons at Liverpool has been at 0.75, 0.84 and 0.90 per 90 without penalties, Kane over the last two seasons has been at 0.57 and 0.67. Over a full 38 game season that's a gap that amounts to 9 goals.
Even at Bolton, Sturridge was scoring at 0.74. Kane's obviously the striker you'd rather have on your roster because of fitness reasons but quality-wise there's no debate to be had.