Yeah, my firsts answer indeed is that they have strength 10. And that's pathetic for an orc. Other orcs might mock them, saying that they're "As weak as a human" or something like that.
And sure, you could invent some weakening curse or something like that. So if I was playing a halfling in your game, could I invent such a curse to drop my strength to four, and gain more point buy points from it so I can minmax my other stats?
I mean I see PCs as people with heroic potential. Gifted noobs. But not as super special chosen ones. There are many such gifted people in the world, some eventually become legendary heroes, some die in a ditch.
Ultimately you of course can always come up with fictional justification for anything. Curse, blessing, bit by a radioactive owlbear, you name it. I just don't think such an approach where the PCs are expected to be unique superheroes is compatible with a splat based game design. Perhaps my halfling was blessed by an angel to have wings, perhaps my trasmutation wizard has uncovered secret art of fleshmending and thus can cast all healing spells etc. Simply put, if I play a splat based game, I want the splatss to define things and actually tell us something about the reality of the setting. If I want unique heroes not bound by such limitations I play a game that is actually designed to build characters from scratch and where I can freely mix and match anything.