I'm pretty sure chronologically Arms still precedes Rangers.
I don't think so. My memory is Legend
takes place in 2265 or so (although it's never firmly established), while Arms
takes place in 2267. The rumor mill said that if Legend
had gone to series, it would have been used to wrap up the dangling threads from Crusade in some way.
Of course, it doesn't matter much since the two movies don't overlap in plot much at all.