I agree, and as I said in my original post Vito would 'stick to his guns' and resist the drug trade, only to find out later its impossible to win.

However if the Sollozo hit failed to injure him I don't think Vito would have had the element of surprise like he does in the movie. If he is not injured then he would have 'show his hand' immediately. Instead, he is in the hospital while Sonny starts a war, then Mike comes out of no where to whack the Turk, and then Vito misleads the five families into thinking he(they) will keep the peace, allowing Mike to whack all five and lead the way out west. Family saved.

So, ironically, it may have been the temporary disabling of Vito that won the war for the Corleones b/c it sets in motion Mike and allows Vito to lie in the shadows and strike his unsuspecting enemy.