In my opinion, there's a huge difference between "long term planning" and "dealing with the random events as they occur". Some titles are more random than others, and in EU3, for instance, any plans I make are subject to constant change as the AI shuffles its alliances and guarantees for no rational reason. Vicky2 is a bit less random, but it's still evident when Spain allies with Russia, then breaks the alliance a year later to ally with the UK, which soon breaks its alliance with Spain to ally with Russia, who it just defeated a year ago in a war. You can only plan so far, because the RNG secretly rules the world, and decides what you can or can't do. All you can do is be prepared to take advantage of the opportunities when they occur.
HOI3, on the opposite end, has very limited randomization. Most of the events WILL happen, and the AI will activate them on or near their historical dates. The thinking is DEFINITELY strategic, planning how to maneuver around the obstacles which Paradox has designed into the game to push it toward a "historical" outcome. You can play the lead-up to war in a dozen different ways for almost any country, but the background situation itself will not vary much from one game to the next until war breaks out, unless you go out of your way to affect it.
Personally, I prefer a game where the events are "mostly" determined by the (mostly historical) driving ideologies, cultures, needs, and objectives of the individual countries, with a bit of randomness on the edges to affect the "tipping point, and will therefore occur if/when the AI feels that conditions are favorable to press them, within the constraints of the game. Since the exact point is slightly randomized, you can't predict EXACTLY what will trigger it, or when. The events are sill present, but whether they trigger or not, and if so, when, depends on slightly variable conditions and random events that make minor short term changes with possible long-term consequences. Picture Japan having a naval "minister" suffer a random scandal shortly before trying to push through plans for Pearl Harbor....and his plan is narrowly refused. The goals haven't changed, but the timing and methods might.
That means, countries like Germany will look for ways to open up access to scarce resources, and look to incorporate other Germans and former "German" land, no matter WHO is at the helm, but the methods and constraints will depend on the leadership at the moment. Change the leaders (coup, election, random heart attack, whatever) and the methods may change, but the underlying cultural ambitions and goals are still there. In far too many cases, the driving forces behind the key actors is missing in games, so the random behavior of the countries is often neither credible nor desirable. HOI3 in its initial (massively buggy) release ATTEMPTED to represent some of those factors, with realistic Relations, Cores that represented ideological goals, historical claims, and other real motivating factors, and some attempt at allowing the game to flow "naturally" from there. Sadly, the lack of restraining factors meant that nations spammed alliance offers (and accepted them from almost anyone), declared wars for momentary silly reasons, and otherwise behaved in unrealistic ways to the point where it wasn't playable. Often, WWII didn't happen at all unless you started it yourself....even as the Allies. The "mostly on rails" game that it was patched into was a pale shadow of what it promised to be. HOI4, on the other hand, took away all of the driving motives behind the events, and then tried to make it "flow naturally" from a set of humorously unrealistic "National Focus Trees", where the AI simply follows them no matter how stupid they are under the circumstances: I have 50 divisions scattered around several different continents, the other country has 200 concentrated on my border.....DECLARE WAR!....because the NF Tree said so. Oh, looks like that increased World Tension, so now I can also declare that other war I couldn't do earlier.