It's not a true RPG, it's more of a strategic set-up and honestly semi-realistic. I believe there is a saying "the best laid battle plan falls apart after the first shot is fired" or something like that.
Basically, you strengthen your squads, deploy them to the best of your ability, and pray they execute the plan as intended lol.

...That said, a bit more control would be nice, but as some have said, it would shorten the lifespan of the game due to people being able to 3-medal many maps in one or two tries, since without the randomness of arrow nodes and battle it would come down to "are your squads strong enough for map X?" which is answered in one run, two tops. It's frustrating quite often but you just deal with it and lean towards being overpowered than on-point.