No I don’t do the same as Pentagon
Both Russia and China (your enemies of choice) possess shore-to-ship rockets that can hit ship up to 2-3000 n.miles away, whether in a convoy or sailing individually. They don’t need torpedoes, bombs or guns to sink ships. They can do that from the relative safety of their homeland.
Whether they will waste such valuable weapons on lowly merchant ships, when they can be better deployed to hit aircraft carriers and other naval vessels is of course a question for the experts.
It is hard to hide a large convoy, or battle group, even if the ocean is large. I would think that Russia and China would know the position of any large convoy, or naval fleet on the move.
Take out their satellites you say?? Who knows if they are able to hack into feed from US and allied surveillance satellites, or other top secret sources of information?