Remember my "Society Variety" theory I've mentioned often on here? (Really should make a blog entry specifically about it sometime, heh.) It's actually important that any large-scale system has a variety of "talents" (or abilities) of its pieces, including both societies of fully sapient beings like us and advanced technological systems. (This is why the idea of "everybody must conform" is a lie, at least to an extent.)
Different talents, in this case, are better suited for different maintenance tasks. And even when multiple people of the same type (say, Ta-Matoran) are all doing the same job (say maintaining the Great Furnace), different specialties within that job are possible as well. Even if they aren't officially defined, but you just have a range of talents.
If they were all equally balanced identical units, they'd all adapt the same way to all problems, which has its advantages, but nobody would be particularly suited to any unusual challenges, and if those came up, the whole system might crash. So it's best to have a range of balanced overall, and various specialized units as well.
So I would presume that "personalities" or specialties would be an inherent part of the GBs' designs for them.
Edited by bonesiii, Dec 04 2012 - 04:40 PM.