This is the edited first 13.

A jubilant whoop escaped Vatar’s lips as he cantered away from the herd with the other two boys. Torkaz returned Vatar’s grin, confident, as always, that his plan would work.

Vatar leaned forward, urging his horse to go faster. Torkaz and Fenar recognized the challenge to a race. The three boys galloped across the open grassland, but Vatar did not keep the lead for long. Fenar leaned forward until he lay along his horse’s neck and flew past the other two boys.

“Great idea, Vatar!” Torkaz said when they reined in their horses. “Now we’re almost far enough away from the herd and the herdsmen don’t suspect a thing.”

Vatar didn’t tell his friend that he had just felt like racing for joy. Torkaz rarely complimented anyone on thinking of something he hadn’t,

This is the previous first 13

A joyful whoop escaped Vatar’s lips as he cantered away from the herd with the other two boys. They were going to get away with it! The herdsmen had no reason to suspect their real plans or to try to stop the boys. Now they could explore despite the adults’ attempts to prevent them.

Torkaz returned Vatar’s grin, confident, as always, that his plan would work.

Vatar leaned forward, urging his horse to go faster. Torkaz and Fenar recognized the challenge to a race. The three boys galloped across the open grassland, but Vatar did not keep the lead for long.

Vatar would never be able to outrace his younger brother. Fenar was by far the best horseman of the three.

What do you think? Better?

A jubilant whoop (I like jubilant here over joyful) escaped Vatar’s lips as he cantered away from the herd with the other two boys. Torkaz returned Vatar’s grin, confident, as always, that his plan would work. (Nice)

Vatar leaned forward, urging his horse to go faster. Torkaz and Fenar recognized the challenge to a race. The three boys galloped across the open grassland, but Vatar did not keep the lead for long. Fenar leaned forward until he lay along his horse’s neck and flew past the other two boys. (NICE)

“Great idea, Vatar!” Torkaz said when they reined in their horses. “Now we’re almost far enough away from the herd and the herdsmen don’t suspect a thing.” (something a little awkward here, starting with Now we're... suggest maybe breaking up the phrase into two discrete sentences?)

Vatar didn’t tell his friend that he had just felt like racing for joy. Torkaz rarely complimented anyone on thinking of something he hadn’t, (I don't like racing for joy. I do like him racing for joy but I think I'd rather Vatar show us what that feels like. And you get the feeling Torkaz isn't real nice from the last sentence fragment.)

This is the previous first 13

A joyful whoop escaped Vatar’s lips as he cantered away from the herd with the other two boys. They were going to get away with it! The herdsmen had no reason to suspect their real plans or to try to stop the boys. Now they could explore despite the adults’ attempts to prevent them. (I had the same awkward feeling on this passage starting 'their real plans...to prevent them'. I am not sure why.)

Torkaz returned Vatar’s grin, confident, as always, that his plan would work.

Vatar leaned forward, urging his horse to go faster. Torkaz and Fenar recognized the challenge to a race. The three boys galloped across the open grassland, but Vatar did not keep the lead for long.

Vatar would never be able to outrace his younger brother. Fenar was by far the best horseman of the three.

What do you think? Better?

But really they are both good, nice job.