Coincidence because the key difference between them is why they each avoided war.
Britain was still recovering from the effects of WWI, so another war was the last thing he wanted, so he hoped that letting Hitler have half of Czechoslovakia would sate Germany and prevent another war. He was voted out.
Long Feng on the other hand could not give an elephant-rat's ass about the rest of the world, he just wanted the power over the Earth Kingdom and set up a nice hermit kingdom for himself where he lived in the lap of luxury. He was usurped by Azula and apparently spent the rest of his life in jail because he was never truly in prison until he lost the loyalty of the Dai Li. Also to cement how much of a paranoid dumbass he was in said thirst for power, he popped his own bubble by holding The Avatar's pet captive instead of just giving Appa back, let alone bragging about what the city's really like, so that's Bond Villain Stupidity on top of Bond Villain Stupidity.
One was well-intentioned but ineffective and the other was ill-intentioned and effective up to a certain point.