IIRC, the "Essentials Edition 2183" version was basically an earlier version of the codex. When it was printed ME1 was still being made, and certain parts of the codex were later changed, so it isn't entirely reliable. But things that aren't directly contradicted can generally be assumed to be true.
Careful reading of the part about biotic krogan shows that they aren't surgically created however. Instead, the surgery was attempting to raise the power level of a biotic krogan, who are almost all low powered.
So as far as I can tell Miranda (and maybe her "sister") is the only one whose biotic ability was intentionally added instead of a lucky accident. And even with her it's quite possible that her father just grew a lot of clones, exposed them all to element zero and only kept the ones that developed biotic ability.
From this I conclude that the reason that Okeer didn't make Grunt a biotic is because he didn't have the technology to do so. Most likely that technology doesn't even exist (yet).
Modifié par faeriehunter, 26 janvier 2011 - 09:26 .