Agradecemos a @DavidW pelo link e as primeiras ideias em seus comentários. Eu acho que ele está certo de que o livro que o OP está procurando é realmente Ordem Natural.
Rahl já é um escriba quando o livro abre no Recluce, ele não aprende o ofício como Cerryl aprende mais tarde
Rahl pode usar a ordem instintivamente e usa esse controle para facilitar a vida de si mesmo, como a citação de Goodreads dá
To make sure things go his way, he uses a small amount of order magic in opportunistic moments, but his abilities are starting to get the attention of the Council magisters. He's not like other ordermages, the same rules don't seem to apply to his magic. And he has a bad attitude too. It gets him sent to the mages' training school for testing, and then banishment to Hamor, where his learning continues under dangerous circumstances.
Rahl é pego usando a ordem de forma inadequada e enfrenta testes em Nylan para prepará-lo para o exílio em Hamor.
A aula de idiomas é onde Rahl precisa ingressar em um grupo de falantes apenas hamoriano e aprender o idioma dessa maneira.
Leyla sighed. “You don’t really believe a word I’ve said. I just hope you read the book carefully. If I can’t get through to you, maybe it will.” She stood. “Right now, there’s little point in saying more. Let’s get you over to the Hamorian class.”
She opened the door and waited for Rahl to join her in the corridor. He glanced down at the wear-polished stone floor tiles. For all the cleanliness of the building, there was also a sense of great age, from the depressions worn in the stones to the slight rounding of the corner stones.
“We use immersion language studies. You’ll step into a setting where people are doing simple tasks, and all of them will be speaking Hamorian. You are not to say anything, except in Hamorian.”
“But… I don’t know any Hamorian.”
“You’ll learn,” the magistra said. “I’ll meet you in the eating hall after the midday meal to take you to meet Sebenet. Now… this way.”
She opened the third door on the left, motioning for Rahl to enter before her. She followed, then bowed to a magister dressed in crimson. What the magistra hadn’t said was that, a number of the other students were children, some as young as eight or nine.
Rahl had no idea what she said, but when she gestured to Rahl, he bowed slightly.
The magister replied in the Hamorian Rahl didn’t know, then motioned for him to join several children seated on cushions in the corner of the chamber. One held up a book and opened it.
As he seated himself, Rahl thought she said something like, “Sciensa livra y miendas.”
Between the activities and trying just to hear the words, Rahl had a headache by the time the midday bell rang, and the class was over. He might have learned a few words.
Citação de Ordermage Natural - capítulo xvi
Existem várias menções a escudos, para evitar o caos e também "escudos leves" durante a história, para que possam ser o que o OP lembra.