Do geshe degrees change over time?

I have read several different conflicting pieces of information about geshe degrees. I assumed geshe is a rank given at the end of study. But, [according to Wikipedia](https://en.wikipedia.org/wiki/Geshe#Conferral_of_the_Degree) : > At the conclusion [of their studies] the abbot assigns each candidate to a category of geshe according to his ability. There are four such categories, Dorampa, Lingtse, Tsorampa and Lharampa, Lharampa being the highest. After this, in order to qualify, the geshe candidates are not allowed to miss even one of the three daily debate sessions during the subsequent eight months. Does this mean that one can first get a dorampa and then a lingtse later, similar to how lay people earn a bachelors and then a masters?