GFO, TMO, RFB, FOTRS are all mutually exclusive. There are versions of RSRDC that are said to be "compatible" with GFO, TMO and RFB. "Compatible" means that the game doesn't crash. However when you run RSRDC it tramples the supermod you installed it over and basically obliterates the supermod. Traveller's Mod is all about frustration and how much instability and game difficulty will you accept before just giving up in frustration. It has more bugs than features.
OTC is a matter of opinion. Mine is that it is of incomparable quality but the premises of the mod are total fallacy. OTC postulates that before and perhaps during the war, the US military rented every ship, both military and commercial in the Japanese fleet, sailed it to a harbor and took complete and accurate measurements of them so that your recognition manual would be 100% accurate. Additionally, the Japanese agreed that no modifications of cabin heights, masthead heights, etc would be allowed during the war and that no additional shipping would be built until they lost the war. Obviously no such agreement would ever have happened and it would have for the OTC mod to reflect reality. It begs the question that if we rented every ship the Japanese had for measurement purposes, why did we give the ships back? We could just have kept them and prevented the war.
In my personal copy of OTC, because the gauges and periscopes of OTC are so much better than stock I kept them, but I trashed the database and recognition manual changes. Configured like that it's the best overall quality mod there is.