Well they don't just know the "general location" of a ship. The article addresses the problem of terminal guidance (using out of date information) but it seems to treat targeting issues as fatal flaws, rather than acceptable risks. It doesn't matter if it the hit rate is 25%, they're going to fire ten of them. There might be collateral damage due to misidentification? Boo hoo, you're in an all out war.

I get it, you're convinced ASAT warfare is inevitable. The reality is it's akin to MAD. No one's going to start that war because it's lose-lose.