Dragonborn & Kobolds

Heya, I've been looking at creating a Reptilia faction that's mainly involved around using strong elite dragonborn (like those from D&D, not Skyrim : ) ), and small puny massed kobolds.

I'd like the kobolds to be small-sized, but the only way I've seen to have small-sized models is in the dinosaur (troglodyte devolved tree) tree. Obviously, kobolds aren't dinosaurs, so I wondered whether this is even possible at all? I've noticed goblins and imps (humanoid domain) aren't small-sized, so that's not an option either.

I want the dragonborn to have the draconic bloodline traits and have them remain kinda 'pure'. Kobolds can be as much mongrel-born / mix-and-matched as needed as long as it still kinda feels kobold-ish.

Would this be possible, since imo Kobolds and Dragonborn are both a draconic sort of species (kobolds being a very devolved offshoot from dragons, but not enough to be on the level of drakes)? I've thought about not taking the draconic bloodline as a faction trait so that I can keep the kobolds low-costed, but I don't like having to pick the draconic bloodline as class trait for every 'dragonborn class' I'd make, since all those different classes would become pretty much identical then.

tl;dr: I feel like what I want is to have 2 different draconic bloodlines; 1 elite-focused for dragonborn, and 1 low-costed one for kobolds.

Is this possible(I don't think so, R.A.W.), or are there any other approaches for this idea?

Thanks in advance!