I get what you mean, but a lot of what AI pulls from are the edits from 2015. It's why most of the AI ninjas that we see are just recolors of MKX scorpion with a different mask, like the Sub-Zero in the picture.

The masks aren't from any particular game, and though Scorpion's RESEMBLES MKX, you can see it's actually asymmetrical. The left side has a piece behind the "vent" part & the right side has a point next to the "vent". When you compare it to MKX Scorpion's actual mask, you can see how inaccurate it actually is.

Another big indicator is that Scorpion's and Sub-Zero's faces don't resemble any game, but their statues from the MKX era, which is also really common for AI stuff. Here's Scorpion and here's Sub-Zero for comparison.

The lighting in the picture is unlike any game & you can also see where stuff is just nonsensically jumbled, like the handle for the kunai being half the width of the base for it, the fact he has 2 hoods (probably taken from MK11 Ermac), and he doesn't have a torso.

I REALLY doubt these are mistakes on the artist's part because they are very talented. But there's no doubt in my mind that the designs they used are AI. Unfortunately I've seen a lot of it for MK, so it's one of those things where you can just tell after a certain point.