WI no double envelopment at Cannae 216 BC ?

I'm not much of an expert on ancient hist, so here goes:

How would hist have been affected had Hannibal's destruction of the Roman army at Cannae in 216 BC not been successful ? Could the Carthaginian attempt to destroy Varro's army thru a double envelopment have been thwarted by better Roman generalship ? How about effects on military affairs further down the track, such as with the Schlieffen Plan which was reputedly designed with the intention in mind of Germany inflicting a Cannae-style defeat against France ?

Given the overall level of incompetence in Roman leadership, I doubt the campaign would have changed all that much. They would simply have taken their troops, faced him elsewhere, and be beaten again. Of course it is just BARELY feasible that they would actually draw the right conclusion and give command back to Fabius with the army still in being, but we're talking Rome here. They win wars in spite of their generals.

If the Romans had actually won Cannae - I don't think they could have but if they had that would alter the course of the war enough to evict Hannibal earlier, possibly concentrate the fighting in Spain rather than Italy and Africa, and deter Macedonia from intervening. Hannibal needed to win all his battles, the Romans just one. That might have interesting implications for the Eastern policies of the next generation. Maybe Rome's next enemy is not Macedon but Epirus or Egypt? Or the city leagues of mainland Greece? That could lead to a greater rejection of 'Greek values' and a concomitant greater acceptance of Hellenistic styles of govermnment earlier in Rome. Where does it lead? L Cornelius Sulla Augustus? Would the emperor of Russia be called the Tsul rather than the Tsar? I dunno. But Cannae, while becoming a military legend, actually decided very little, so I doubt it would matter all that much.

I recently read a rather interesting take on Cannae...

...it basically said, despite the destruction of the Roman army at Cannae, the battle did more harm than good to Hannibal; Fabius preserved the army, but allowed Hannibal to raid the countryside unopposed. Cannae showed the Romans and their allies that they would fight; and so no Roman ally defected to Hannibal. I don't know enough Roman history to comment, but it sure is an interesting idea.