A little o’ column A, a little o’ column B methinks.

They’re very young, so a big portion of it can definitely be chalked up to “kittens learning to controls their claws better” as well as “learning from pain reaction responses” as well as “being less playful as they get older”

They kind of all describe the same thing. More stab times, less stab amount (until lots of age, then stab). Same is true for most cats, to varying degrees