I don't know but this is my guess............
Spermatogenosis requires multi-gland participation to be triggered. I personally think GH alone will increase Spermatogenosis, thus sperm count.
In the presence of High Testosterone levels, I don't think GH will solve a low sperm count. Irrespective of GH, high test causes negative feedback to the Hypothalamus and Ant. Pituitary which ceases production of LH and FSH and hence, no swimmers.
Somebody hollar if I'm off.......