[Vocabulary] Have much lower command of English

[Unregistered]

Students from rural China have much lower command of English.

----------------

Question：

Should we have to say ‘have a much lower command of English ’ I/O treating command uncountable as the original sentence is written？
Thank you.

 

[Raymott]

Students from rural China have much lower command of English.

----------------

Question：

Should we have to say ‘have a much lower command of English ’ I/O treating command uncountable as the original sentence is written？
Thank you.

It would be more common to use 'a', but not necessary.
"Everyone has command of at least one language."
"Everyone has knowledge of at least one language."

I don't know what I/O is, apart from Input/Output.