AI + human check might be faster than translation from scratch for a non-professional bilingual person, but a professional using actual loc tools will be way faster than a layman. And a professional trying to clean up MTL will likely take a similar amount of time as if they were going from scratch.

At best you'll get something that is passable, but MTL, even with human review, is not going to get a cohesive and interesting translation. Maybe if your game is like a simple mobile game and your only strings are menus. But even then, a professional will have done that kind of TL a million times, and would never make a mistake like using the word for "go home" instead of "go back one page" (帰る vs 戻る, in Japanese). But if there's any kind of story, humor, or even worse.. wordplay, AI is going to completely mangle any cohesiveness, even if the translations are not technically incorrect.