Tumblr user scienceshaman asks, “Why do so many of the races have a +1/+1/+1 stat distribution instead of the +2/+1 distribution that baseline 5e has?”
Primarily it’s to give build flexibility so the new species can explore a variety of classes. 5th edition appears to have a narrow +2/+1 baseline on the surface, but they utilize subraces to give a wider breadth of options so the +1 or the +2 is often not attached to a single attribute. Because our species don’t have much in the way of subraces, we ended up giving a number of them 1/1/1 spreads to help with their overall flexibility.
The template that I based the species on actually comes from a few of the non-core 5e races which have the 1/1/1 model of stat distribution. I find it to be a good distribution that maintains a total +3 bonus to attributes as a whole in a different way. From a power level perspective they’re about equal, each having its own benefits and drawbacks.
Lastly, I had to keep in mind that some of the people who buy the sourcebook would be using it in their own universes. Settings that might include some or all of the base 5e races. To help create a wider variety we wanted to avoid having too much of the same templating as normal 5e. That way, if you’re including Elves, Dwarves, Gnomes and so on in your S&S gameplay the different options really shine. Likewise for people who are buying the sourcebook for new options to play with in their normal 5e games. As much as possible, I wanted things to be flexible.