Shirou even with his ability to project Noble Phantasms is considered a pretty bad mage as well. He can only do three things, project swords, reinforce those swords and use his reality marble, and he doesn't have the mana to do the shit he does during the holy grail war.
Like Archer heavily implies that he can only use Unlimited Blade Works as a Servant, specifically because he has the mana source to use it, he received the reality marble when he died. Shiro has it earlier, sure, but the only route of the three that he uses it in is UBW, where he has Rin to siphon mana off of, and even then, the Reality marble almost immediately starts falling apart. Sure, he has a reality marble that the spirit of the world doesn't try to destroy, but he doesn't have the mana to maintain it on his own until he becomes a Counter Guardian/Heroic Spirit.
As for Projecting Noble Phantasms, outside of the grail war Shiro can only really project his two swords Kanshou and Bakuya, as well as Rho Ais, anything else would be impractical or overkill, and we also again don't know how many of them he can do before he starts running out of mana.
I also forget to mention that he can't use his Reality Marble around anyone other than Rin because it's seen as close to "true" magic and the Mage association would try to kill and dissect him to figure out how he is able to do it.
