Sure. You can be a runt for an orc or a half-orc. But, by nature of NOT being human, even a runt of an orc is still stronger than a human who grew under the same circumstances, and possibly just as strong as an average human, especially if you aren't rolling and the worse base value you can get is 8.
Of course, if you're rolling for stats, you can be weaker than average human even with +2 Str, but I wouldn't be surprised if rolling for stats was reduced to a variant in D&Done or even removed as an option.
20 at any level puts you above the curve, it's NEVER expected by the system, but it's not gamebreaking.