Why did the Romans put a property requirement on those who served in the Kingdom's army?

Property requirement was necessary while serving in the Roman army for several reasons.

Explanation:

Men in a Roman society separated into categories based on their property because soldiers had to provide their military supplies. Only wealthy people could afford weapons and campaigns, which made them more powerful. Men in Rome without property were not qualified for military service. The poor, despite more in population, were for voting. The Romans saw no difficulty with permitting the wealthy to have political authority because they believed soldiers would lose most of the wealth from defeat, not the empire. So, the wealthy soldiers have given freehold to see what was better for Rome.

the answer is use of support