Which ever one you get first I would process it and freeze the trim. If you do the deer first, freeze the trim in weights divisible by four, which makes it easier to calculate the pork and beef you'll need to add.
    The reason I don't over trim venison is because it has no internal marbling, and the fat cover is usually not to heavy. Wild hogs on the other hand can be an absolute nightmare with the amount of fat in and over the meat. I would try to trim off the fat cover and the meat itself should provide enough internal fat/marbling to work well for grinding. I know of one wild hog that we processed that dressed in the 250-300# range and we removed at least 80# of excess fat!
    Be sure the hog has been thoroughly chilled through before attempting to cut it or you'll find that the fat starts to melt as your working on it and you'll have a hard time holding unto your knife.
    I try to keep both my pork and beef trim at least 80% - 85% lean when adding it to venison.
    It is more important than ever to add the domestic beef to the grind because now both the deer and the hog have been living on a mostly wild diet and could tend to be very strong, especially the hog.

Good luck,

Dave & Ruth