It is undoubtedly a mistake and wrongdoing to waste things. But the Arthashastra describes how, in any practice of manufacture, industry or commerce, there is always inefficiency and waste. This cannot be avoided - as in attempting Ahimsa it is impossible to become wholly harmless, waste is impossible to avoid as well. The cost of minimizing the waste should not exceed the waste conserved: to spend time, effort and money saving something worth less than the resources invested in saving it is not wise.
There are also materials which naturally spoil and waste, or which must necessarily be wasted: for example, an orange prepared for eating has a peel which is not eaten. And some byproduct materials, like stone chips from carving a statue, have only low uses (if any use at all). While the peel might be manufactured into a spice, composted or fed to animals, or in other ways utilized, and the stone chips might be made into gravel, the cost of saving that waste may exceed the value of the secondary production. Eventually, though, the waste naturally accumulates sufficient quantity and value to warrant recycling. Thus, it is seen there is a natural, a Dharmic, quality to efficiency.
There are also acts of retail or service which necessarily add a margin to the final product: these margins of brokerage are earned, and not wrong. As are the revenues earned by lending money. However, it can be seen that when earnings from brokerage or lending exceed 5% or 10%, they are generally considered excessive and will be avoided, if possible, by those contracting for the brokerage or loan. And when they diminish below 5% or 10%, brokers and lenders will not find sufficient profit in their work to warrant their risk and effort. Thus, it is seen there is a natural, a Dharmic, value to all effort.
Whether in war or peace, anything to be gained or prevented from loss, all Arthrashastra, must be worth the effort. And sometimes in war this means permitting loss. Just as it sometimes means not permitting loss.
The study of Dharma, Artha and Kama, and their practice by Yoga, is worth every effort - for it permits you to discern for yourself when to permit loss and waste.