I always feel handicapped discussing Jpn because I don't read it and the KANJI are so critical to understanding the language.
That disclaimer made, my "feeling" then, is that "MA" is better translated as "interval" than "distance" in order to introduce the concept of sequence/time over and against the static feeling/implication of something fixed.
FWIW, Draeger wrote of close MA AI as requiring more courage than that maintained farther away. (Not directly pertinent to this discussion, but interesting to me anyway, he also noted that the greater the MA AI, the less taxing was the art on the body, it following that the sword is tougher than the naginata; aikido tougher than kendo, judo tougher than aikido. Naturally, YMMV.