Sorry, yeah, definitely was very poorly worded. I meant to say:
From what I know from reading on Helios-A and Helios-B, we already have a probe which can go over twice the speed of what I thought I saw the comet is traveling at. So couldn’t the probe match its velocity (dunno why I said Delta V before) to the comet, if even just for long enough to land without total destruction?
We probably could if it's travelling at low enough velocity. But if you match its orbit you're just going the same place at it is anyway, at which point "piggybacking" is just code for "getting some company".
And if you don't match it well enough that you end up roughly the same place you're going to have a fast, and therefore violent, encounter.
That remark makes more sense in the context of missile defence than when talking about space travel.