Some tips: You're better off destroying weapons than doing takedowns. Weapons not destroyed will begin to add up over time and new enemies will pick them up. Also using the quick explosive gel can help incapacitate numerous henchmen for longer than cape swarms will. That can assist in keeping the volume of regular goons down once you have to deal with larger opponents. That being said you're gameplay is really solid! Keep practicing! It took me ages to get all the medals in this challenge map haha
Free flow is your friend and lets you bear them to the punch; you can hit them first instead of countering while they’re still in mid swing. Those variations only slow things down. The only one I really rely on is to break the taser, knife, rifle and shield.