Conspiracy theorising is perfectly natural to the human mind. In fact its just a sub folder of theorising. We do it for all sorts, what going to happen in "X " show, whos going to win "X", whos seeing who at work. So its only natural big events should be subject to it. And its not just individuals groups do it as well, oh its demons doing that, or the Russians doing this. Its all part of being human, trying to work out what everyone else's angle is. Nwo, religion,aliens, hollow earth, flat earth, so on and so on is the more extreme end of the stick but it does make for some cool story's. But i would argue cause and effect play a greater part than chaos and randomness.
In history and politics, there is little cause and effect or planning linking the two. Events rarely cause anything, it takes a benevolent, or incompetent, or, very often, opportunistic actor for the events to have any effect at all. The Helvetians' relocating didn't cause anything more than some local uneasiness, it took an opportunistic and indebted Caesar to use it as an opportune excuse to invade and subdue Gaul and make some cash. The Helvetians' moving house can't be said to have been the cause of the Gallic Wars, it was just an event somebody took advantage of. WWI wasn't caused by the assassination of Archduke Franz Ferdinand, but by the incompetent, panicky and opportunistic reactions of several state leaders, one of whom was slightly potty. WWI could easily have been prevented at that point, the supposed cause of WWI by itself caused nothing but the death of Franz Ferdinand. The so-called causes are often nothing but random events without much effect until somebody somewhere decides to act upon them in some way, which is why you can't predict the effects causes have; the presence or absence of an opportunistic actor is also a random factor, as are their intentions. There are no automatic chains of events, it is not physics.
These things may appear random, but all are effects of an cause. Using your examples Helvetians first had been joined by the Tigurini who had been raiding roman provinces not painting them in the best light. Caesar also tried to stop them moving , the Helvetians went on to attack the Aedui who ask for Caesars help and got it. So it went on , cause, effect, cause. Nothing random.
The Archduke and WW1 conspiracy and high political/economic intrigue abound on those chapters. Far far too many players involved to be simple chance. Even the flat tire on your car is not random, a chain of events must have happened to reach that outcome. Unpredictable yes,probability clouds yes. There is a whole other discussion if random even exists. As Einstein said "God does not play dice".
Also it is undeniable that people plan illegal things. And others try guess what happened or is to happen.
Note that for some of the supposed cause-and-effect relations we only have Caesars word from his post-hoc book justifying himself to the Senate.
"Randomness is the property of lacking any sensible predictability" is the definition I use. Ex-post explanations and supposed cause-and-effect relations found after the event don't make the events less random. Maybe it is in the definition of randomness where we disagree.
As to Einstein: he was referring to quantum mechanics, and he was probably wrong. Bad pun.
"Maybe it is in the definition of randomness where we disagree." agreed =) . "he was probably wrong" lol