Actually, that’s kind of what I did for my Mako wig…
It’s a normal wig with a piece of a lace-front wig cut and then sewn into the front of it for the widow’s peak. I extracted from an existing lace-front, so I didn’t ventilate the additional piece, but yes, that can be done, for sure!
The reason I did it this way instead of just using a lace-front is because the lace-fronts just weren’t allowing me to properly style the wig (since the wefts at the top of the head were designed to go backwards instead of forward, making it impossible to make his flip in the front). So instead I opted to use a wig that already had the perfect style, but just needed the widow’s peak!
But since the hair on yours needs to go backward, a regular lace-front might give you better results, because you’ll have that natural-looking hairline all across your head.
Also, buying high-grade wig lace that’s fine enough for a job like this if often expensive, in my experience. You may end up spending $20 on that, so it wouldn’t be much cheaper than getting a lace-front wig in the first place. I suggest checking out the lace-fronts on Arda Wigs! :)
But weigh the options! BTW, Mulan is one of my favorite movies, so that makes me happy! Good luck!! ^__^