2 companies have the same amount of working capital. The current debt paying about of one campany is much weaker than that of the other. Explain?

For so many reasons. One of them simply that one company has more cash than other current assets (such as prepaid expenses,spare parts and inventory ... etc). But the other company has less cash than other current assets (as prepaid expenses,spare parts and inventory ... etc), so it can't quickly transfer them into cash money.

Also cash flow statement is important for Liquidity Ratios.