so are crimes only crimes if you have a chance of succeeding?

ive read before people here defending the insurrectionists saying "it wasnt a real coup attempt because they didnt bring enough firepower to overcome the US army"

1.is that the standard of crimes now? if you go to a bank with only a knife but you are outgunned is it not really bank robbery? how about if you go with a gun but they had multiple guards with guns? do they really make ruling based not off intent or what you tried, but your likelihood of succeeding with the crime? if I attack a larger stronger person with a knife am I going to not get charged with attempted murder because "well you were weaker than them so"

2. the US army is the largest in the world. by that "logic" there can never ever be anything categorized as a coup because no group could ever outgun the US military