The so-called speaking language that Ye Zhen referred to does not mean the ability to speak. Every Demon Soul Soldier can speak, but their speech is extremely stiff and rigid.
For instance, the lowest-ranking Demon Soul Soldiers can only say a few mechanical military phrases like 'yes' 'roger' 'kill', etc. As for the ten-man generals, hundred-man generals, and so on, they can handle a few more military terms, making them slightly more flexible than Demon Soul Soldiers.
However, the thousand-man generals, ten-thousand-man generals, including some special units like messenger soldiers and scouts, are regarded as standard military leaders, true military officers.
When it comes to various military tactics, suggestions, command, etc., aside from the lack of any humanity, they're entirely like living military officers.
