The premise of most Godzillas is that human weaponry is ineffective against it (often including weapons of mass destruction), and in some cases it would only enhance his power.
Trying to kill Godzilla with a nuke is like trying to throw Superman into the sun.
To begin with, both contexts are completely different.
When Nolan arrived on Earth, his mission was to conquer it and enslave its inhabitants. He felt genuine affection for it, and it's implied that were it not for his loyalty to Viltrum, Nolan would have lived there peacefully. Nolan wanted Mark not to awaken his powers so that he could extend that time further, but he had an even greater affection for the empire from which he was born and a desire to lead it forward, especially since by this time he already enjoyed a good reputation within it. Since Thadeus, no one else had betrayed Viltrum, and to be the first to do so, knowing the consequences would be execution, required great courage.
The other Viltrumites, like Lucan and Kregg, arrived on Earth when there were no more Viltrum and it became their new home (for Nolan, it was only a temporary stay). Furthermore, their new mission not only allowed them to grow fond of Earth but also benefited from it, as it made it easier to blend in as ordinary people. They didn't have the burden of betraying the empire, and they already possessed the experience of others regarding the planet, making them confident in that respect, while for Nolan, everything was new.
+2000 years old man vs 15 years old girl take
For this, Joseph will still have Hermit Purple, but his personality and strength are the same as in Part 2.
Omnipotus is often greatly overrated due to all his grandiose statements, but the truth is that a mid-level Viltrumite would probably be enough to defeat him.
Not even Kregg, who is second in command to Thragg, wears it. Do these two operate with a different rank than the rest?
Tech Jacket in the series is weaker than most Viltrumites, but still has low-relativity with them, being stronger than most of Earth's Heroes
Literally the "fight" of Battle Beast against Thragg in the comics: