Agree. We've seen from attacks like Nice that cars and trucks can cause massive damage. Not trying to sidestep Charlottesville, just noting that the scale can be much worse with even a little planning. I actually recall arguments I used to have with my dad where we'd talk about terrorism - my claim was (and actually remains) that there can't be that many people interested in committing acts of terror because it's so easy to just rent a U-Haul truck and do something terrible. At the time, I don't think there had been any such attacks, but it's such an obvious route.
That said, those strike me as more likely to be the sort of planned things (even if they're slapdash planning) that are less likely than the escalation of punches to melee weapons to guns. A lot of people are armed. You don't need advance planning for one of these stupid melee skirmishes to get a lot worse real quick.