Ok, so its more of a gender identity thing. You should modify your opening post though, because a lot of folks don't read beyond that before they respond.
So IME the style should reflect how often you want to have to get it cut because baby hair grows
fast. Lightning fast

If you get a cut longish cut its probably going to need to be recut in three months or so. Here is what I mean:
Right after his hair cut three months ago:

His hair a couple of days ago:

When I was a kid all the boys got "summer cuts" where their hair would be basically buzzed and then would have grown out to a "respectable" length when school was ready to start again. Do people still do that?