The early-cycle LOAs tend to have conditions, such as completing DoDMERB successfully, obtaining a nom, passing CFA. They can receive their offers of appointment at any time in the cycle.
DoDMERB issues can be active well into the spring and even run close to report dates. That can hold things up.
If you look at the appointment threads, past and present, you can see the general trends relating to types of noms. Feb-Mar, the slates start resolving, and there are a pile of them. Don’t forget the SA can go back and choose other fully qualified applicants off a slate, and those appointments are charged to nom authorities they manage, not the MOC.
Principal nominees still have to be fully qualified. Now multiply that by all the slates that might have used the principal nominee method.
College re-applicants start showing up, as their first semester performance is evaluated. SA prep schools and scholarship prep schools start appearing in the spring.
And yes, while the service-connected noms are not in and of themselves competitive, as everyone who is eligible, is given one, there is fierce competition for the limited number of appointments that can be charged to, say, the JROTC/ROTC nom. That is a national competition among everyone who applied with that nom - likely to be more than 9 other people. They must also of course be fully qualified. On a MOC slate of 10, assuming all 10 are fully qualified (medical/DoDMERB, physical/CFA, academic/all other evaluated factors), one candidate’s appointment will be charged to the elected official. Others may receive offers of appointment as noted above or also have earned other noms and may receive an offer based on one of those.
I posted a photo the other day of a Star Trek 3D chess set. Class-building proceeds in a dynamic matrix fashion rather than linear, in a very unique and organic pattern, each year. There is no way of predicting whether a certain type of appointment will appear early in the cycle, or later, and regardless of when the candidate submitted their application. There are general trends but plenty of outliers.