Did Sparta have a strong army on land?

Answer 1

The strength of the Spartan army is that the citizens were relieved from having to farm to support themselves by the allocation of seven serfs each. This meant that they could concentrate on military training, which the militias of other states could not afford to do. This held up as long as their numerical strength remained at a viable level. As citizenship was heriditary, any major losses meant a diminution of the army's numbers, which began in the Peloponnesian War and continued thereafter until Sparta lost offensive military significance and was hard pressed to defend its own territory. A second factor was the rise of mercenaries - from the 4th Century BCE, some cities and then the Hellenistic Kingdoms were able to pay for mercenaries, who were able to train continuously, so that Spartan edge of training eroded along with its military manpower.