Gotcha. I agree impacts don’t arrive on schedule, so something else must be driving the pattern the planet is in right now.
There’s a climate cycle, of a sort, and it is evidenced by the periodic egress of invasive groups going east and west on the steppes, into Europe, the Near East, and China. It isn’t related to the Milankovich model, which is largely a cartload. The point I was making about the non-periodic nature of large impacts is, the impactors may be chunks broken off a much larger object. That object may have just been passing through, or on the short leg of its long, long path around the Sun, or perhaps it broke apart due to stresses of passing by the Sun, and became a train of smaller objects. Since their orbits probably are very similar to the parent body, they’d arrive from time to time in small groups.