If those are the same ones that I tried, the CYMA ones are a bit of a wobbly fit. I had bought my G36C from TA and I even tried some other mid-caps while I was buying them. If it was the CYMA's, we were even able to yank them out with a little force so I would suggest going there and trying it out if you could.
That other one is a little bit of a loss for me. Never dealt with Ares brand midcaps so it's a gamble unless someone has tried those specifically.
I use MAG brand midcaps in mine now. They've been amazing for me since I started using them. I was able to get 4 for $70 from someone I know so its kinda in there in terms of price. Try for find them