This is very true haha. Somewhat of a second class citizen to pilots, but important all the same.
The previous poster covered most of the information that I would share, but another thing that you need to consider is how infrequently and/or competitive those particular airframes are to get. I'm currently a nav who graduated from UCT last year (looking into UPT in the future) and I can say from the numerous drop nights that I saw, the Bone and MC in particular are not so common. If a class is lucky enough to get one to drop, it usually is literally just one. The F15 almost always has at least 2 drop, but since they are the only pointy nose, there are a lot of people trying for them. My dad was an F15E driver and I know a couple dudes at each of those airframes and as previously stated, it doesn't look like they are going anywhere anytime soon. Just work your ass off in UCT and you shouldn't even have to worry about getting what you want!