Eventually, he lost anyway.

Having stopped the war himself after the death of Sonny (who could never have been outfought by Tattaglia the pimp).

And being able to bringing Michael home...whose job it then was to bring the Corleone Family back.

So...as many have responded to the original question, things would've gone pretty much the same had Vito NOT been injured in the Solozzo hit. Different players, different tactics, different timeframes, maybe.

But same results.