I never play more than one route/end in games. If I have to choose between several LIs, I prefer to know as much as possible about them before doing so. Although that certainly doesn't prevent me, at the point, from leaving the game because I am interested in both (or whatever number). I usually never finish games where I have to choose between several different LIs (I only remember one that is in the process of finishing, and I can name quite a few more that I have abandoned). Also, in harem games, I don't like having to necessarily choose between LIs (and not at all doing it without knowing anything about them or knowing very little).
About the example of two groups of 3 girls... If both groups have at least one girl that interests me, I will not choose and will abandon the game. The only possible option for me to proceed to choose is that none of the girls in one of the groups interested me at all (if they all share a fetish that I dislike, for example, or seem unfriendly, or anything else that might make me I don't like them).
Regarding the girls with incompatible personalities... well, the same as for the group. If I am interested in both, I will not choose and I will abandon the game.
In general, the chances that two "facing" LIs will like me at the same time are high (and increase notably as the number of mandatory elections increases)
For all these reasons, I usually prefer to ignore these games (except on very rare occasions)
On the other hand, I don't know the games you name, but I'm not sure if they are to my liking.