Dragonborn of Bahamut in 3e are creatures that are not born, but made by Bahamut, the counterpart to Tiamat.
Tiamat = Takhisis
Draconians are made by clerics of Takhisis (as in the power of Takhisis makes the Draconians).
4e made the Dragonborn into a playable race in the PHB and left out the 'of Bahamut' part. Which is slightly different in 5e again, just like the Drow...
There are some young folks that say that Warhammer stole the Orcs from World of Warcraft, but those that are a bit older and know, Warcraft is a game with Warhammer serials filed off. Similar things happened with Starcraft and 40k btw. Warhammer pulled inspiration from everything, unknown if they were inspired by D&D or Lord of the Rings, as at the time Citadel (the miniatures arm of GW at the time) was producing both D&D and LotR miniatures...
And the Orcs from Tolkien are not the same as the Orcs in D&D, or in Warhammer, or in Warcraft, but boy were they inspired by them. The same holds true for the Draconians vs. Dragonborn.
And while the Council of Wyrms setting (and other sources) had things like half-dragons, that was a similar, yet separate path that was ultimately abandoned with almost all the other half-xxx species/templates.