Dragonborn is not a small statured race.....
The only reason I see it more likely we will see Gnomes or Durgar more likely over those sooner is because they models are already in game files. So less work has to be done to release them as a playable option.
Currently all the work is in place where they could release barbarian, gnomes and durgar with little to no effort on there part as oppose to Dragonborn and Half-Orcs which do not have any models currently in the data mined game files to be usable. I however there are already Chat dialogues for both so I would not expect it to be a long time before models come out for both. Implimentation may take alot longer. It will probably be 1 or the other and more likely that it would be dragonborn purely because they are more requested on net overall than half orcs though i think both do need to be added at some point. Half-Orc would work well with fighter and barbarian but Dragonborn could be a good addition to paladin, barbarian, warlock, bard, and sorcerer. It would also test there ability to make a non human figure as a race since pretty much every race currently in game is more humanoid than not they still have more humanoid features. Dragonborn would be a much larger step seen there face would not have a human like appearance as well as both HALF ORC and DRAGONBORN would use the larger humanoid models.
The reason I see Dragonborn as a much larger push concept is its 1) more requested on net. 2) It has more class options it would see regular play with. 3) It tests large models. 4) It tests there ability to make a non-humanoid faced character being added a more monstrous race coming in.
Given the choice id like to see it enter with paladin as that hits both check marks for good options for the class. However it would make more sense to release it with barbarian as the race lines up with making the barbarian not just feel like gale in a toga. Barbarians have to be bulky and brutish or it just does not feel like a barbarian. Half orcs could also fit this but it doesnt check all the boxes. I feel like half orc will probably come after aasimar and dragonborn just because of player design.
If I had a choice id say release dragonborn with paladin and annouce half orc with barbarian for a 2 month follow up or vice versa but I dont see that happening. Just because the 2 more requested races are Aasimar and dragonborn which leads me to think it would be dragonborn with barbarian and then aasimar with paladin but it could be done as half orc with barbarian and dragonborn with paladin as a second since both do have dialogue in game files and aasimar does not currently. I am just thinking from a developement stand point and interest stand point what would hit the most people being happy.
I also contradict myself a little saying that as Monk is probably higher on the wanted list than some other classes currently and releasing those could be a high sought after option with Githzerai // Aasimar as well.
Gnomes I feel would come with more wizard subclasses. And more tiefling subraces would probably come with sorcerer. I think its a matter of what works out well with what in cohesion. If they wanted to make a big patch and wow people a bit. Druid was a nice addition but I felt they could have done more.
