Something I have experimented with myself. Now, normally, I think the only REAL motivation for more males vs females is due to most games being done by a greater populous of men and/or written/created by men. On average, I'd say we understand men and are better at creating a wider range of male characters (and often end up going with the basic, strong headed girl, dumb blonde, and diabetically sweet). I often hated how that was the 'norm'. In one story I wrote, I accidently ended up with a cast of 12 guys and 2 girls (and no, it was no harem). I just didnt want to create any 'stereo types' among the girl and had more ideas for a differeing male cast.
Now, Dies Irae was where I wanted to make up for that. Sure, right now, there seems like a lot of guys (with six even being featured on the cover. In all honesty, there are only about three more main males aside from them) but in the end, the girls actually dominate in numbers (with about 13 females off the top of my head, but pretty much double the males). I, personally, wanted to do something different in that regard. Without making the game 'girly' I wanted to keep the format, but change things up. So I spent A LOT of time developing a cast of girls who pretty much break the stereotypes (some fall slightly into those categories, but none fall into diabetically sweet or air headed).
ANYWAY! Point is, I think as long as you make a cast in which people CARE about, it doesnt matter if there is an equal amount of male and female characters, or if one dominates over another. Like I said, personally, I wanted to change up the standard formula. I mean, often you see more males; but many times, games like Tales, tend to try to find a balance. But ultimately, no one really cares if one side has more than another; just as long as the cast is well made.
That's my two cents at least. If it helps any, haha.