That is only kind of true. In real life you can hang out with a friend and still go on a date with someone who is interested on the same day, it's not either or. You also have the choice as a person on who you would want to spend time with. Say like at the movies for example... Everything in this game is so restrictive. There is so little wiggle room to explore your option that you almost have to be a stalker with the LIs. The only one you've know for longer than work week is Ashley but in order to stay "faithful" you have to stick to them like glue.
Well since I was talking about starting several routes at the same time, or about somehow being present at two places or being in different conversations which happens simultaneously, but yeah, I do agree that it should be possible to start the routes with the LI's at multiple points, instead of being forced into going for a very narrow set path and only that it's only via this path that this LI is possible to pursue.
So I think we can agree on that some of the "variable checks", which opens up for the paths shouldn't be as they are atm. since they restrict how you can play, if you are interested in a certain LI. But you should still focus on the woman you like, but I think the largest problem is actually the time frame in total, as you mentioned yourself, it's only been 5 days.
It would make it so much easier for the dev to make it a true harem game without all the inconsistencies if the story had a longer time frame, since it would make it possible for the multiple relationships to develop properly and for the women to interact with each other and so on.