Please do pay attention to wording. The incident in the second post above, shows that the Japanese military vessels were docked...that means not moving. the Vietnamese vessel had been moving, and somehow managed to rub against two different ships within a short span of time--obviously.
In the first report, the Japanese ship had been moving. It was, however, in the port. The fact that all three ships were there at that port, however, is due to their having been on an exercise...not that they were, at the time of the collision, doing maneuvers.
The most likely, obvious problem here, would be port congestion, would it not? But, the second event, could be suspect in some way...maybe.
Otherwise...it's all coincidental. In all probability, there is nothing 'happening' at all, beyond simply things happening, as that what the universe is.