In the Pool of Radiance series, the best race for a Cleric (and past the first game, the only viable choice period) is Human. There's no dispute about that: Half-Elves can't level up past level 5 (and are therefore not able to learn any healing spell that isn't horrendously weak), and other races are not allowed to be Clerics in the first place.

Contrast that to the early Wizardry games: Not only are Humans not the only viable race for Priests, they are in fact the worst choice: Their Piety is the worst of all races. That means that Humans need to spend more bonus points at character creation, while a Dwarf (for example) could spend the points elsewhere, or start with even more Piety (giving a better chance of learning the important spells as soon as possible).

Fortunately, later AD&D games have higher level caps for Clerics, making other races at least somewhat viable. (For games that go that high, I consider 11 to be a minimum requirement so that the character can learn Heal, which is the only non-weak healing spell (as is its Wizardry counterpart MADI, if you don't count the unreliable and costly (MA)HAMAN).)

It seems that, in contrast to Gary Gygax's preference for a Human centric campaign, the authors of Wizardry must have preferred one where the other races were dominant. (Note that Humans don't even get any advantage to counterbalance their low base Piety.)

Well, Wizardry wasn't directly inspired by AD&D, but more by old Plato games like Oubliette.

And the race level limits in AD&D makes more sense in the pen&paper version since it takes so much longer to reach high levels than in the computer games, and "investing" in a Human character may never pay off.

In Wizardry Humans are more "generic", while other races are more specialized. Humans have no strenghts, but no weaknesses either, statswise. But Gnomes have bonus to Wisdom, which makes sense since the name "gnome" is derived from the old Greek name for wisdom.

So the games have different approaches, which is good. Would be boring if all CRPGs used AD&D races.

Actually, in Wizardry 1-5, Humans do have a weakness: their Piety is low. Furthermore, due to the lack of any advantage, Humans end up with the lowest stat sum.

Fortunately, this was fixed later in the series: Humans have the highest stat sum in Wizardry 8. (In that game, I actually like to make my Bishops human because of that. Of course, I have something to say about Bishops in that series, but that's for another topic on a more suitable subforum.)

One similarity between Wizardry (1-5) and AD&D: Notice the healing spells? Same spell levels, similar amounts healed. Same 2-level gap between the first two healing spells. Same gap between the 5th level (weak healing) and 6th level (full heal + status recovery) spells.

Most early RPGs (Ultima, Wizardry, etc.) were attempts to play D&D without actually infringing on the copyrights of actual D&D. These guys grew up playing D&D and they wanted to know how to do it on the computer. If you look at the Japanese names of Final Fantasy 1 monsters, they are almost all taken from the Monster Manual. The Ahriman (the big floating yellow one-eyed monster that hits you with death attacks) in later Final Fantasies is actually a distant relative of the beholder.