Striders can spawn in stacks of three or more

I suspect this may be working as intended. I've seen them spawn this way from a spawn egg (stack of four) and naturally (stack of two as normal jockey formation).

If the babies on top of babies weren’t floating, it would be pretty cute.

I would have just filed the bug as something along the lines of "multiple baby striders riding each other have wrong positioning, I just think they need to fix that issue.