"There are eight desks."
Did you have a particular sentence order that you believe to be correct but isn't accepted?
In my Japanese classes, they said that putting the counter right before the verb is the easiest order. Although it's possible to put the counter earlier in the sentence, it involves more complicated grammar. It looks like you need to put の between the counter and the noun being counted.
“Numeral + Counter + の + Noun” https://www.wasabi-jpn.com/japanese-grammar/how-japanese-counting-systems-work-in-a-sentence/
Although word order might be somewhat flexible in Japanese, my understanding is that there isn't an unlimited amount of flexibility. Certain words really do have to go in a particular order. I've also heard that some word orders sound a lot more natural than others. So even if it's technically okay to vary the order gramatically, it might sound a bit odd.
"There are two basic sentence patterns:
Numeral + Counter + の + Noun, e.g. ３冊さんさつの本ほんを（買かう / 買かいます）
Noun + Particle + Numeral + Counter, e.g. 本ほんを３冊さんさつ（買かう / 買かいます"