Well it sounded like the branch option was not going to close off any paths so it could still work, but using the example of the vampire vs werewolf choice why wouldn't I want to do both? In that example if I had to choose it would always be the werewolf path (based on the ending for each). So the vampire path would be kind of wasted.
If the game had been set up from the beginning with your choices leading to more branches it might make sense but the story up til now has been pretty linear and your choices have mostly boiled down to pick the option the girl likes (or not). So my vote would be for the do everything option as well.
One way I could see branching working for this type of game would be to have a linear part of the story that happens no matter what and then some extra stuff that you can choose what order you do them in. The game is not set up that way now but for instance what if Luna was your favorite girl so you chose to go do her day of the dead party right way (before it happens in the current game), that unlocks Luna's sex scenes sooner than the other girls. Same deal for the others, so maybe you focus on Dahlia and Alex initially and you get the threesome with them that I assume is coming eventually earlier than if you worked on other girls paths first.
So you could still have it set up so you get to do everything but you have some different options for which things to do in which order and maybe you have a few extra bits thrown into certain scenes depending on how you set it up.
