That seems like the most likely scenario.
Either that or Steve Trevor wasn't the only guy to crash on the island. Somehow, a small force of enemy troops may have ended up there too.
That, or maybe Ares or someone brought them there for some reason.
Seen plenty of both. Never saw him do anything close to that super-leap.
He doesn't dodge bullets. "Dodging bullets" means you literally get out of the way of bullets that are already heading toward you. Over in the Rumbles board, they refer to what Batman and similar characters do as "Aim dodging." He doesn't dodge bullets after they've been fired. He dodges the people holding the guns before they fire. He just sees to it that he isn't where the bullets are going to go.
And it still changes nothing. There's evidence that the Amazons are superpowered. There is no evidence that they are not. Until we see more footage that expands upon this topic, we're all just speculating here. The important thing is that the Amazons are taking on a force of gun-wielding professional soldiers with swords and arrows and they do not appear to be losing.