Does EU IV have a possibility to play historical?
It basically is a very historical game - most Paradox grand strategies are. EU IV starts in 1444 with the map and nations mirroring the time period closely. Although the starting map has changed over the life of the game. Mainly those changes are incorporating new nations into the game, as well as what I called their interpretation of the relative diplomatic/governmental situations at that time. It was a time of great flux in that regard...well for the next few centuries really.
Take France for example. At game release, you add the nation of France with its provinces. But portions of what one would consider France today was broken into the vassals of Orleans, Aquitaine, Bourbon and some others. All of which were real subject states at the time. Then at some later release they decided to just go with a much larger France without all the vassals...again technically correct. Then again later, they broke up France once again even breaking out Norman provinces into the vassal Normandy. Regardless, France was just as powerful in each iterations. Vassals are completely subject to the master and their armies fight with you, plus you can diplo annex them.
Burgundy is another great example. At release, Burgundy was basically a blob with its provinces. A very strong nation and rival to France. As you may know Burgundy was a power at this time but was shortly on its way out of existence with the Succession. Anyway, later the broke up Burgundy into a still strong Burgundy plus several vassals and personal unions of Dutch and Flemish states.
Events in the game are historical and historically timed with some variance and randomness, such as the Burgundy Succession itself and the later the appearance of Netherlands and defection of Dutch states. Very detailed and historically accurate events across the world. That includes the religions as well such as the Reformation circa 1500AD and subsequent Holy Wars.
However, of course, the game can be played to alter history from that point forward. The historical events and happenings are still coded in but in some cases based on your actions you can great affect or eliminate certain things, or mitigate the results like the Reformation.
Of course, to answer your question directly you can try to role-play the game as historically as possible, at least from the perspective of the nation you are playing. The game is engineered t play as historically as possible in terms of events, but there is certainly the randomness as well. You have Ottoblob and the Big Blue Blob (France) and Mingsplotion, so any thing can happen with those nations.
HRE stuff is wild in this game. Probably one of the first things you'll want to do in this game is play Austria.
One way I think of EUIV is a very deep and complex game of Risk..ha
Actually, there's a HOMM VII released in 2015. (I've not played VI or VII) V was released around 2006. I played it a long time ago, but recall graphically it is far superior to III. But III is consider by most the best of HOMM. I thought V was good though. I did play the heck out of it.
Oh..I was just checking on something I found out both King's Bounty and HOMM were both successors to the original 1990 King's Bounty. In fact, the same developer of the 1990 KB made HOMM 1 2 and 3.