Understand desperate obsession with need for backup striker, but if/when Harry does get injured and we do have a backup striker just for the sake of it that player will obviously be nowhere near as good or effective as Harry. So it's all very well saying if we don't get backup in, it will be criminal mis management. But the chances are that if we did get backup, chances are he wouldn't slot in perfectly. It takes players particularly forwards a while to adapt to new systems and I imagine adapting to a system as intricate and as gruelling as Poch's system would be far harder than any usual tactical scenario.
So I wouldn't be as apocalyptic with rage as many others if/when we don't get another striker. There is little guarantee he would hit the ground running. I mean look at Soldado. Quite obviously a quality striker but imagine if we had just bought him now without any prior knowledge of his history.
Do you'd rather run Kane into the ground and play someone out of position instead because its a risk that the player may not adapt straight away?
Every transfer is a risk and there's never a guarantee attached but a player who has proven he can score goals in the PL, who can play with Kane as well as on his own up front is a risk worth taking. If he doesn't hit the ground running then at least he has 6months to adapt for next season when we'll no doubt need someone when Kane needs a break after the Euros (like he should have had after 21s this season).
It's not only the need for a striker in case of an injury. It's to protect a young player who would otherwise have to play a ridiculous amount of games in a PL season. The long term impact of fatigue/overuse is a worry too.