EDITED: Please see the postscript at the bottom!

Your ancestor was the grandfather of the Maharal? Cool! The Maharal was a fascinating person, despite never having made a golem...

I'm not sure where you got the phrase "head of the state of Ashkenaz," because as you correctly realized, there was never any such thing. Ashkenaz is a word which is found in the Bible- first as the name of Noah's great-grandson in Genesis 10:3, then in I Chronicles 1:6 and in Jeremiah 51:27 in reference to nations. The nation of Ashkenaz mentioned in the Bible was probably somewhere in the Middle East, but hundreds of years later, in the time of the writing of the Talmud, Gomer (the father of Ashkenaz in Genesis) is identified for the first time with Germany (or as it's called there, Germamya). A few hundred years later, in the 11th century, scholars such as Rashi (probably the most important Jewish biblical and talmudic commentator) were referring to German as "the language of Ashkenaz."

From then on, Ashkenaz essentially meant Germany. It became the name of the specific religious tradition in practice in the Jewish communities in what is now Germany and northern France, which at that stage was quite often very separate not only from the Sefardic tradition in Spain (which acquired its name in much a similar way to Ashkenaz- Sefarad is also mentioned as the name of a location in the Bible that certainly originally didn't mean Spain, but which Spanish Jews were proud to coopt, calling themselves, from the Bible, "the exile of Jerusalem that is in Sefarad" [Obadiah 1:20]) but also from the Provencal Jewish tradition, the Italian Jewish tradition, the Polish Jewish tradition, etc. Later, when Jews began leaving Germany and northern France en masse following expulsions and the Black Death (and its ensuing pogroms) in the 14th century, they brought many elements of their traditions with them, and even when they syncretized a lot of these traditions together, blending, for example, the Ashkenazic and Polish traditions (with, in fact, Polish traditions subsuming the Ashkenazic ones to an extent), the name Ashkenazic still stuck, and by the 16-17c the whole European (with the exception of Mediterranean European) Jewish tradition was basically called Ashkenaz, with smaller categories within that.

Maharal lived at various points in his life in Poland, Moravia, and Bohemia, all of which, by the time he lived (in the 16th century) would basically be considered Ashkenazic, though not fully yet. He was a highly significant and impactful rabbi in terms both of his influence in his life (as the rabbi of large communities and yeshivas in Nikolsburg and Prague) and his influence after his death (he wrote many Torah commentaries and books which are still used frequently today). In hindsight, he can be considered one of the leaders of the Jews of the era in terms of his impact, and that's about as much as he could be considered "the head of the state of Ashkenaz" or whatever. Again, the phrase disconcerts me- it just doesn't make sense.

EDITED: YES! I have maybe possibly figured it out! This article, from an exhibition catalogue for an exhibit on the 400th anniversary (yohrzeit) of Maharal's death, was EXTREMELY helpful in ironing this out, and I recommend reading it if you're interested, but here goes, so far as I can tell-

Based on rereading the question, I'm assuming that you're no longer talking about Maharal having this title, but rather his grandfather. That doesn't really seem to be historically accurate, but here's what I've found:

The grandfather of Maharal, R Chaim, was a real person. In fact, he was probably two people; it seems as though both of Maharal's grandfathers were named Chaim. However, your family tree is still possibly wrong. An erroneous work called Megillas Yuchasin (the Scroll of Ancestry), written by a relative of Maharal, averred that R Chaim of Worms was Maharal's paternal grandfather. I checked a few of the many genealogies online which claim to include Maharal and a large number of them made this mistake. However, while it does seem clear that R Chaim was the father of Maharal's father, Betzalel, he was not from Worms and the information about him in the Megillas Yuchasin was incorrect. We basically know nothing about this R Chaim, except that he must have been born after the date that you mentioned- he probably lived from about 1460/70-1520 (for details of the calculation, see the article).

What we DO know is about the other R Chaim, who was almost certainly Maharal's maternal grandfather- he died in the mid-1560s, far too late for both the dates you mentioned above and for the dates of Maharal's paternal grandfather. He was from Issenheim, in Germany, and one of his sons was named R Jacob of Worms. He was the uncle of Maharal, according to Maharal's brother R Chaim of Friedberg, and he was also the Reichsrabbiner of the Holy Roman Empire. R David Gans, a rabbi and proto-historian, described the post as being "Head and President of the Rabbinical Court for all of the Ashkenaz" (though he also makes the mistake of referring to R Jacob as Maharal's paternal relative). This is very possibly where the title to which you refer, "head of the state of Ashkenaz," came from (even if it's still a very weird way to translate it)- though as I mentioned, it would refer not to R Chaim but to his son R Jacob. It would also imply that rather than, as in my original comment, Ashkenaz referring to the Jewish tradition, it would refer to the Holy Roman Empire.

This is all I can come up with as far as what you're saying. I have no idea if it's helpful, but from the article and its footnotes it seems to be historically supported. If I find anything new, I will update.