Not to mention RC are for whales mostly, since you have to discharge Gold+ units (not very common if you aren't spending) and event units take a huge hit to their trade-in value. The only way to "farm" RC is to farm Demon Crystals on Thursday and trade for Cyrus (the only TP unit that's also in shrine and therefore gets full trade-in value). however, that's 100 DC for 20 RC and will take ages without SC spending which defeats the purpose of using this method in the first place (other than avoiding silvers mixed into your shrine rolls).

Anyways, AW fodder is generally a bad use for gold because you can farm silvers in events, CC them and use that instead. Using gold units as AW fodder is something only full-time whales would do. CR/SU for commonly used units is recommended by me, especially the first one (which is guaranteed). Rarely used units depends on if they're niche like Anemone (though this might become a common use down the road when we get more story areas) or if they'll almost never be used due to having better alternatives (like in my previous post's examples). Units you'll likely never use I'd keep one copy for scene completion and trade the rest.