I'm glad you included me as one of the authors, although I'm a little embarrassed to be listed there. After all, I only came up with the idea, and you did all the work. Thank you.
By the way, a question - did you change the stats of these units, or did they retain the stats from the dragons?
And another question - it would be nice to add a couple of interesting abilities to them. The Phantom could be given an ability like "Dragon's Roar" or something similar, in the style of the Nazgûl's cry from The Lord of the Rings. In practice, this ability would simply cast the "fear" or "despair" spell in a certain radius around the dragon.
And the Champion could be given an ability like "Dragon's Breath". That is, when this ability is activated, the dragon itself would attack with a normal attack, instead of the rider. Just change the effect of the fire to green, for example.
The riders on horses, since they don't fly, could be given a regular teleport.
Just some thoughts...
By the way, you clearly didn't understand the joke from the previous author.
With his link, he probably wanted to say that you made a mistake in the word elite.