I mean, you _could_, just like you could choose to say/write the number "150,000" in English as "fifteen ten-thousands" instead of "one hundred and fifty thousand" if you wanted to.
It would sound somewhat weird and potentially confusing, though, as that's not how large numbers are typically counted in Japanese.
(Incidentally, note that the standard reading for 八千 is はっせん, not はちせん. You have it right in the first instance, but in the final line you've changed it to the latter.)