It might look like Ashton had a plan, but in all honesty, he didn't. All he knew was that he was facing an enemy who had more than 6 levels than him. Normal strategies wouldn't work against him and there was no way he would have survived a head-on battle with the Gorillan.
Also, he could not use the rest of his genes because Seven could appear there at any moment. And Ashton did not want him to know his secret because Seven would have immediately reported it to Jonathan. Who in turn would have had Ashton dissected in hopes of obtaining the secret to his powers and possibly replicating it.
But Ashton wasn't that big of a fool to take on the Gorillan without thinking about everything. He was aware that the Gorillan had lower intelligence and agility than him. While He wasn't sure how he would use the Gorillan's low intelligence against him but he knew of a way to use his agility against him. Like he was doing now.