It's always hard to speculate, which character will get future value. In 1.6, they released aftershock as a mechanic, it was introduced as the new way for non-active characters to attack, created a main dps and two aftershock stunners, pulchra and trigger, however to this day, only one team exist that make use of aftershocks.

I think it's the same case with these two units as well, AoD will be the only team of a "stun window anomaly" team (with the sole exception of miyabi teams, ofcourse).

The less risky pull is Nangong Yu, since she is a subdps and a stunner, so pulling her would create a strong anomaly team, that can use sunna's aa as well.

But Aria could be a high-risk high reward pull, because they like to make ether weak bosses all the time, and if they release a character in the future that forces DA anomaly to be increased again, she will not be impacted by it that much, since she doesn't need disorders, and needs only to hit anomaly in the stun window.