I always thought Sparta had the right idea of no walls. They basically trap you inside as much as keeping the enemy out.
Also Rome had a real weakness in the aqueducts.
a state in which 70%+ were slaves (Helots) doing the work and indentured for generations
Where there was no family life - boys from 7 were separated from their families and all young men lived together until 30 when they could start a family. The boys were continuously trained as soldiers
homosexual relations, pederastry etc. were encouraged as a means to keep the unity of the military units
They had no inkling of culture or trade, unlike the Athenians (who had their own problems of course, but imho, not as severe).
Spartan society was one-dimensional, purely dedicated to war, a dead-end society that could not even innovate -- Philip the Great of Macedon was able to smash their phalanx with the clever use of cavalry and side-attacks.
The Roman way was simpler -- "on this side of the line (the Servian walls) is Rome. Outside that is not Rome. We got no problem with those outside, but there is friction on the border, so we'll expand a little bit, then a little bit more..."
The Roman way is exemplified in the difference between the armor and strategy of the Romans and their enemies -- the Romans had huge shields protecting their soldiers and smaller offensive weaponry. They worked as a team.
Does anyone think that Hannibal could have played ANY strategy which would enable him to win against Rome? I can't think of any -- Carthage seems to be to be doomed right from the time Rome pushed through to the Naples area.
Carthage was a Punic/Phoenician/Canaanite enclave in Berber/Imazhigen/Numidian territory. It was a mercantile, sea empire, not a land one. They could not defeat this awe-inspiring organization that was Rome, imho