What might be a major flaw (depending on the company) with using the ROA. Hint: it has to do with the Assets from the balance sheet.

The profitability of a company influences its value and the amount of income it generates for its owners. Two financial indicators that measure the profitability of a company are the net profit and the return on assets. The percentage of net profit is the amount of net profit divided by the amount of sales times 100. The percentage of return on assets is the amount of net profit divided by the total value of the assets of the company times 100. The percentage of net profit, or net profit margin, measures the ability of the company to generate surplus cash. The percentage of return on assets measures how efficiently the company is using its resources. Using financial indicators in business performance measurement allows you to compare different business types. You can define operating objectives for your company, but such objectives differ for companies in different markets or industries. Even when a company generates a profit, it can go bankrupt if it has big expenses due in the short term and has no money to pay them. If you want to compare your company's performance with a wide variety of other companies, financial indicators are a neutral tool for evaluating performance.

ROA is calculated from the Booked value of assets in the balance sheet.

Some specific areas of concern --

how is land valued on the books, how are depreciated assets valued on the books, intangible assets are another concern.

Are these assets on the books really reflective of the true value of the assets?