Yes, we have talked about it a few times that evolution doesn't happen necessarily the same way and they will look like exactly the same. It was just a cheap option why the Ancients can be played by humans. It could be still explained
1. one of the human group have moved back in time and they became the Ancients
2. one of the Ancient group have moved forward in time
I am just a pharmacist, so I am not a DNA expert, but we have talked somewhere that if the ATA gene is completly random genetic skill, then how it is good for the Ancients? What is the use of ATA genes if not every Ancient can use it in emergency cases? And if it is inherited like a recessive gene amongst Ancients, then most of the population should carry it in the Pegasus galaxy. They have never bothered to explain how the humans showed up in the Pegasus galaxy. Are they all ex-Ancients? Or have they brought people there from the Milky Way? Or have they genetically degrading like the Asgard in time? I know the writers are not biochemists, but they have walked into this trap in the lore. I like technoblablabla, but I love believable technoblablabla.
The Furlings would have been in the Stargate : Worlds game as a race called "Straegis" which was conquered by Ra. There are some concept art and they look like combination of elementals / chrystal beings / angels wing.
I would like to see more biology related themes in a future spinoff. Maybe the whole stargate syste, was a test of evolution as every planet is a potential test lab for the Ancients. You know planet size, sun-planet distance, sun type, sun lifecycle, local planet rotating time, seasons, environment etc. Everything can influence the evolution. And if they can dial each other it can go in both ways, so it can be a complete catastrophy or something really positive. Such environment related subplots could be a new focus of Stargate next to history, adventure and obviously action.