Rockin Robbins mod is not 100% "compatible" with FotRSU, but that is a relaive term anyway, since he altered the characteristics of the two torpedoes. I do not recall if you get the homing torpedo early in his mod or not. Perhaps someone else can speak to that... Anyway, the "warning" from JSGME is just that, a warning that you are going to overwrite files. That is the nature of a mod, so about all you can do is to try it, see what happens, and go from there. Just be aware that RR's torpedoes can also take the player's sub out if you are too close to the detonation of the torpedo

- it can be great fun though! If you don't like it, or it trashes something else in the game, just use JSGME to remove it, and you should be good to go again. Loading a Saved game both before and after using the mod might not work though.