Gwen said she can alone take down all Hybrid Warships as Anodite. And Azmuth explained that all earth weapons combined are not enough for a single Warship.
Lets see what earth has got and what can Gwen do..
Earth has a mighty hero Ben ten that can transform into Humangousaur (you may say that Omnitrix is not related to earth in origin,but Azmuth's words were for Ben too so please bear with me)
Humangousaur's one of biggest feat '
He threw an alien hover board in orbit from Downtown
K.E=1/2mv^2
K.E=0.5*10*(20 km/s)^2 (I am considering hover board to be 10 kg in mass bcz it seems to be almost ten kg.Now for Velocity (escape velocity is 11.2 km/s ,as hover board has to tear through earth crust so 20 km/s is good)
K.E provided by Humangousaur =2*10^9 Joules
Earth also had Dwarf Star which increase potential by almost several times. Lets down play it to be 10000 times
So Humangousaur with Dwarf Star has potential of 2*10^13 joules
Say it is enough to take one warship down
And there were Thousands in episode War of worlds (taking 100 thousand ships)
So energy required =2*10^18 joules to blow all ships
A single blow from Gwen is hence equal to 500 Megatons of TNT explosion
It is Ten time more than Tsar bomba the most powerful weapon tested untill now.
Gwen's single blow=10 Tsar bomba