Forgive me if I'm not understanding but if this is your advice then the multi-vehicle should be fine, no? It at least claims to be a suitable replacement for dex-II/dex-III so unless I'm missing something, it should be good enough. At least, that's what I'd think. Again this is my first mopar/a body so my apologies.
I think this is kinda what I was trying to get at with my original post. I know older engines/transmissions tend to be more lenient/forgiving than modern ones so if that's the case, does the difference really matter all that much?