This is where Jenkins really broke out... she didn't fake the Amazons. She found some extremely powerful women, and others who were willing to work to become strong, and she didn't have to CGI and fake her way through those scenes.
Of course, it's ironic that Wonder Woman is the least muscularly developed of the group, but then, she's got her own kind of inner power that the others don't have. She has a true superpower, while the rest of the Amazons are "merely" 99.999% percentile human athletes.
Even Doutzen Kroes, a model who might be the most beautiful woman on the planet (IMHO), loved getting much stronger... and it shows. (Of course, I grew up near Holland, MI where there were all kinds of blonde Dutch girls, most of whom were athletic, so the Dutch (technically Frisian in Doetzen's case) qualities are very much burned into my brain.
Also, there were a lot of very cool scenes of Amazons competing and training (in costume) in this video that didn't make the movie. Hopefully, we'll see some of those in WW2.