That dragon "titan" provokes both feelings of disappointment and satisfaction. It is disappointing because it is not a real mech and just a dragon dressing up as one. It would have been awesome to see how the titans would look as four legged equine shapes. On the other side of that coin it is satisfactory to see the ponies fighting along side other species since it serves to show that they are still the same ponies from the show just in a darker future and not 40k humans in pony skins.
It's precisely as you said, I want this to be more than a simple species swap. This is to be one of the infinite possibilities of Equestria's future, where mistakes were made and ponies were thrust into a constant struggle to survive in an uncaring universe.
Using dragons as the Titan legions was a challenging decision, but I felt it was worth exploring. The idea of a planet thats core is made entirely of dragons (Mars) sounds pretty cool in my head, where adepts of the Marechanicus feed the dragons gems mined from across the empire and rely on them to fuel the massive furnaces of their manufactorums. With the steel they forge, they create massive plates of armour for the dragons, who in turn serve to protect their worlds.
It's a rather interesting symbiosis, if I may say so myself. ^_^
I haven't quite gone that far yet. The assumption is that their system would be a similar as our own, but I'm pedantic enough to want to make sure. In either case, it should be a world close enough to pony homeworld.
Which begs another question, what would the ponies homeworld be called? Equestria seems to be the name of their nation/continent, so it might be peculiar if their planet was named similarly. I... I'll figure this out at some point.
Well the fact that Celestia controls the sun pretty much makes it impossible for it to be a system like our own. The show has provided enough evidence that one can claim with some confidence the sun orbits their world not the other way around.
As for the name of their home world? No idea really. Equus is just the most common fan name. Maybe Ptolemy/Ptolemai or something simmilar after the system's arrangement?