Sun vs. Rome

The Gemara in Yoma 20b has the following cryptic beraita:

ת"ר אלמלא גלגל חמה נשמע קול המונה של רומי ואלמלא קול המונה של רומי נשמע קול גלגל חמה

The rabbis taught: If it were not for the sphere of the sun, the sound of the multitude of Rome would be heard, and if it were not for the sound of the multitude of Rome, the sound of the sphere of the sun would be heard.

I found a few different explanations for this:

• The Maharal in Be'er Hagoleh says that the sun has a rulership over the earth and the Romans have a rulership over the earth. Each rulership has a partner ruling with it, so each cannot rule with full force since its rulership is neutralized by the other. He explains "קול" to mean bringing its potential power to fruition. So, if it were not for the sun's rulership, the fourth kingdom would be overpowering, and if it were not for the fourth kingdom, the sun would be overpowering.
• The Maharsha explains that the fact that the sun only rules during the day and not at night shows that its rulership is not forever. Therefore, if it were not for the sun going down, I might think that the Roman kingdom would last forever, but now that the sun goes down, I now know that the Roman kingdom won't last forever. And the opposite is true too - if it were not for the Romans having had ruled over the entire earth, I might have thought that the sun's rulership over the earth is a sign that it is a real rulership, but now that I see that even humans can rule the entire earth, I now know that the sun's rulership is not real.
• The Keli Yakar on Bereishit 32:25 brings down a gemara in Bava Batra 16b that says that Avraham Avinu had a precious gem that anyone who saw it would be healed, and when Avraham Avinu died, Hashem hung it on the sphere of the sun. The Keli Yakar explains that the precious gem is really the publicizing Hashem's existence to the world, and so when he died, Hashem hung it on the sun to show the world where Avraham Avinu himself discovered Hashem's existence - from knowing the sun's daily path, one can figure out Hashem's existence. This is why the angel fought with Yaakov Avinu only until Alot Hashahar, since he couldn't get Yaakov Avinu to deny Hashem's existence which is evident via the sun's rising. This is why in our gemara, if it weren't for the sun announcing Hashem's existence, then we'd be left with the sound of the Romans who deny Hashem's existance.
• The Malbim on Yehezkel 43:2 says it means that if it weren't for Hashem pushing the sun from East to West, the natural state of it going from West to East would take effect, thereby denying Hashem's existence.
• The Ben Ish Hai, in Ben Yehoyada, says that the word חמה represents the Torah since it stands for: ה=the 5 books of the Torah and the מ"ח=the 48 ways of acquiring Torah. Therefore, if it weren't for the Torah learning that we do, the Romans would have destroyed us, but the power of Torah weakens them, and if it weren't for the Romans, we would have been able to learn 10 times as much Torah had they not weakened our Torah learning through their harsh decrees.