According to the animation the 222 actually uses AP shots and the Luchs HEI shells. This could explain the difference in anti personell effectiveness. But the anti vehicle effectiveness would be better.
How can you tell that? I'm interested in what "according to the animation" means.
Also the 222 has higher penetration and damage per-shot than the Luchs, which I suppose does support the "AP shots" theory. The 222 has 35-35-35 while the Luchs has 25-20-15.
Interestingly, that makes the 222 one of the very few vehicles with flat penetration, along with the KV-8's 45mm. They may be others but I haven't seen 'em.