In the current game structure level 20 is the highest any Dino will get a hybrid. That is not to say they will not add a new level where a dino needs to be at level 25 for a hybrid though… Just sayin’.
You could say you have enough DNA to cover your bases if you have a Dino to level 20 and are Maxed on DNA. It may never get a hybrid, in that case you wasted time darting. If it ever does get a hybrid you are ready to fuse. But thinking long term, every Dino will eventually be getting a hybrid and most hybrids will become a component of another.
Or… With any update any Dino can get a buff or a nerf. We have had common that make the lineups of the top teams that were worthless an update before. Think Draco 2. And… desirable common that got tossed due to the same process. Think Tanny.
For Majunga: I feel it is ripe for a hybrid as it is pretty useless as it stands. With a little TLC its kit would be pretty decent on a Legendary or Unique. Opinion here and just as an example.
And, as has happened in the past… About the time that once overly abundant DNA becomes very desirable… They all but disappear from the game. I dart whatever comes across my path. I level them up as I max on storage so it is ready for a hybrid at any level required. This also saves on coins a I am not spending them all at once.