I have two of them in operation with 2x 27" monitors but side by side.
But when I look at what I have, I would say: Basically yes.
If the mountings are far away from the lower monitor positions, it may be that the second monitor is too short. But if the mounting is relatively close to the final position of the lower monitor, the length should be sufficient and stability should be sufficient in my opinion & experience.
Hope this was helpful.