Its easy...
1) First group, the apostles and EVERYBODY that knew the apostles up until the GREAT APOSTASY. Never mind that Jesus said that nothing or nobody could undo what he had done.
2) Then almost 2000 years with NOBODY really anointed, yeah, they may have thought they were, but Jesus and Jehovah were waiting for Charles Taze Russel to show up and set everybody straight. Then, from CT Russel until the death of the last guy that knew him....that was the elite group of, faster, stronger, better than the apostles or First century anointed.
3) Then, when that last guy died off, there was another group...they knew some of the guys that knew CT and Franz and all those guys, but they weren't part of that group. At least, they didnt tell anyone they were. You see, Franz had said that the anointed had ALL BEEN CHOSEN and that anyone else that claimed to be anointed after 1935 would be a faithful, long serving, REPLACEMENT. Well, convenient enough, when Franz was buried at the launching pad, these NEW and IMPROVED full-boat anointed appeared on the scene. They were stronger, faster, better, yes, much better than the second group and DEFINITELY better than the apostles, after all....ALL PROPHECY relates to them.
4) Then, you have another group. These are the ones that didnt know the second group, they didnt overlap. They just saw how important the overlappers had become and started to think, "Hey, these overlappers are going to probably die in this system and who will take over the nice leased cars, and the really nice apartments at HQ when they do?" "We will!" So, you have people who start partaking in their late 30's and 40's, "LOOONNGGGG TIIMMMMEEE" servants just like Franz had said.
Does that clear it up?