I don't think this makes sense. A notable set of events in countries history is the effect of unexpected changes: revolts, great leaders coming and going, bad harvests. Starting conditions are quite important, and geography and demography probably critical, but by no mean all that there is. Let us live with the randomness of (simulated) human nature.
Imagine the Ottomans without those 5 good rulers? Or the Hapsburg without the love power?
I would say these seeming "luck" factors are actually not really luck, but the strength of underlying institutions, geopolitical situations, economy, etc....On the other hand, seemingly strong nation that disintegrated shortly after few failures, however massive they were, -- such as Burgandy or Hungary-- were probably not strong at all. Ottoman in its heyday could bounce back from many failures she had.
Anyway, I second that Burgundy is way overpowered, at least if it manages to take Bar. I would say it needs to be more decentralized (and loose some of its cores/missions), or make Flanders the lesser partner in PU in 1399. Although Burgundy did control the most wealthy part of the world back in time, its degree of control over its domain was very low. Prussia around 1750, on the other hand, was not the most populous or prosperous state. However, its administrative apparatus and military was unmatched in its capability and efficiency, allowing it to fight 7 years wars (BTW, Frederick the great is way too overrated, IMO -- but then, people tend to see heroes instead of underlying forces). Currently, EU3 does not simulate this very well.
About OP, I would say Castile, GH, Timurid, England, Algeria, Austria, and Hansa are overpowered. Actually, I don't think Ottoman is underpowered -- rather, the problem is with other game mechanics. Most notably, AI nations have way too high capacity for operating overseas, allowing England to send its stacks into Asia Minor (and vice versa). Given the abundance of crusader droppings in her area (and the web of alliances, guarantees, spheres, and DoF), it tends to drag OE into problems with more far European majors than they should. Adding hordes and opportunistic Turkish minors, it is a recipe for disaster. In fact, OE was perfectly fine back when there was no guarantees.
I forgot to mention, but being HRE emperor is way overpowered. Fortunately, it is easy to tone it down via mods...
Oh, and France was overpowered historically -- at least, after it managed to consolidate its control over modern-day France and began its quest for becoming the centralized, absolute monarchy.
In fact, govt types should be far more influential (and restrictive) than it is now. Time to make a mod, I guess.