Considering its Bulbapedia, I would also take that with a grain of salt, considering its a fan-site - more-so than the anime. It's name coming from "the reverse of the Japanese transliteration of orichalcum" is a huge stretch. If anything its much closer to "oracle" than "orichalcum". I still think that the spikes isn't really a justification for its Steel-typing - moreso, it seemed to be an afterthought of the design. That said, I do understand more or less why Lucario is Fighting / Steel now. I still think other typings are more fitting for it, but alas.
You have to remember that Psychic in the Pokemon world isn't just Psychic like we know it in the real world, and that Aura in the Pokemon world (as evident by Lucario) works differently than it does in, say, Dragon Ball. Aura in Pokemon lets Lucario read peoples emotions, thoughts, and can understand human speech. The main things to get from this is emotions and thoughts - both are things that are tied deeply into Psychic types (Thoughts is obvious, while Emotions is less obvious but is still connected to Psychic thanks to Azelf, Uxie, and Mesprit). Meanwhile, if we look at what learns Aura Sphere (excluding Clawitzer and Blastoise since they got it to abuse Mega Launher): Mewtwo, Mew, Togekiss, Dialga, Palkia, Giratina, and Mienshao. Most notably, all of them get it by Level-Up except Togekiss who must use a Heart Scale. Dialga, Palkia, and Giratina probably received it because they debuted the same generation Aura Sphere was. That, and their canonical powers are so immense that it wouldn't be outlandish to believe that they can control aura. Mewtwo, Mew, and Mienshao are probably the most notable ones, with Togekiss being less notable but still interesting. Mienshao more than likely gets it because of the fact that it's "the Martial Arts" Pokemon, which ties it closer to the chi idea of Aura that is closer to reality. However, this doesn't disprove what I'm suggesting the "Pokemon" concept of Aura is - merely that Aura is probably more of a combination of theses ideas. Both Mewtwo and Mew are Psychic-types, and both have connections to emotions. When the Pokedex isn't busy talking about Mew being the original Pokemon, it mentions that "Apparently, it appears only to those people who are pure of heart and have a strong desire to see it." How would Mew be able to tell if people are "pure of heart"? Reading their aura isn't far fetched, not to mention that Mew gets Aura Sphere at level 100, showing a mastery of Aura. Mewtwo, meanwhile, is born directly from Mew, and has a bad relation to humans as seen by its origin story. If we still insist on using the anime for reference, then Mewtwo also has the ability to speak with humans. Togekiss is odd and I don't really have a reasoning for it learning it - I guess it has some form of connection with emotion via happyness? idk.
Meanwhile, admittingly, Ground is a bit more shakey than Psychic, but I should explain it more. I don't directly mean Anubis = Ground, as Fighting / Ghost would make more sense as you said for a direct connection. The idea was that Anubis => Egypt => Desert-themed => Sand => Ground. Sand = Ground also fits in the Pokeworld thanks to Sand Attack and smaller things such as Sandslash and Hippowdon (Sandstream) being Ground-type. There's also the fact that it learns Bone Rush, which not a lot of mons do (only Marowak and Mandibuzz do outside of Lucario). You could say it's because it's a dog, but there's a lot more to that then just that - otherwise Stoutland would also learn Bone Rush. Bone Rush probably ties in with the Anubis motif (bones are usually associated with death, and Anubis has a canine look to it. Thus - Bone Rush). Both of these things hold ground for Lucario being Ground.
You have to remember that Psychic in the Pokemon world isn't just Psychic like we know it in the real world, and that Aura in the Pokemon world (as evident by Lucario) works differently than it does in, say, Dragon Ball. Aura in Pokemon lets Lucario read peoples emotions, thoughts, and can understand human speech. The main things to get from this is emotions and thoughts - both are things that are tied deeply into Psychic types (Thoughts is obvious, while Emotions is less obvious but is still connected to Psychic thanks to Azelf, Uxie, and Mesprit). Meanwhile, if we look at what learns Aura Sphere (excluding Clawitzer and Blastoise since they got it to abuse Mega Launher): Mewtwo, Mew, Togekiss, Dialga, Palkia, Giratina, and Mienshao. Most notably, all of them get it by Level-Up except Togekiss who must use a Heart Scale. Dialga, Palkia, and Giratina probably received it because they debuted the same generation Aura Sphere was. That, and their canonical powers are so immense that it wouldn't be outlandish to believe that they can control aura. Mewtwo, Mew, and Mienshao are probably the most notable ones, with Togekiss being less notable but still interesting. Mienshao more than likely gets it because of the fact that it's "the Martial Arts" Pokemon, which ties it closer to the chi idea of Aura that is closer to reality. However, this doesn't disprove what I'm suggesting the "Pokemon" concept of Aura is - merely that Aura is probably more of a combination of theses ideas. Both Mewtwo and Mew are Psychic-types, and both have connections to emotions. When the Pokedex isn't busy talking about Mew being the original Pokemon, it mentions that "Apparently, it appears only to those people who are pure of heart and have a strong desire to see it." How would Mew be able to tell if people are "pure of heart"? Reading their aura isn't far fetched, not to mention that Mew gets Aura Sphere at level 100, showing a mastery of Aura. Mewtwo, meanwhile, is born directly from Mew, and has a bad relation to humans as seen by its origin story. If we still insist on using the anime for reference, then Mewtwo also has the ability to speak with humans. Togekiss is odd and I don't really have a reasoning for it learning it - I guess it has some form of connection with emotion via happyness? idk.
Meanwhile, admittingly, Ground is a bit more shakey than Psychic, but I should explain it more. I don't directly mean Anubis = Ground, as Fighting / Ghost would make more sense as you said for a direct connection. The idea was that Anubis => Egypt => Desert-themed => Sand => Ground. Sand = Ground also fits in the Pokeworld thanks to Sand Attack and smaller things such as Sandslash and Hippowdon (Sandstream) being Ground-type. There's also the fact that it learns Bone Rush, which not a lot of mons do (only Marowak and Mandibuzz do outside of Lucario). You could say it's because it's a dog, but there's a lot more to that then just that - otherwise Stoutland would also learn Bone Rush. Bone Rush probably ties in with the Anubis motif (bones are usually associated with death, and Anubis has a canine look to it. Thus - Bone Rush). Both of these things hold ground for Lucario being Ground.
I actually forgot about Ice Shard when submitting that last night. Ice Shard has been added to Sawks movepool, as it would make sense considering that (at least going with my justification) its an icicle man. Also changing Mega Lucario's ability to Sand Force to fit more with the design since Jajoken said we could change Mega Luke to nerf it back to OU