Yes I think its stocked maybe a little overstocked. No ram would ever work in that tank no matter which fish u took out rams are very sensitive and they would get torn apart or it would just hide and u would never see it. Are the convicts females if the cons are either both male or a pair.( Which if u have a male and a female its pretty much guaranteed a pair lol) I would remove them and get two females or some hrp there better looking and u wouldn't be overstocked IMO.
Yeah you could add more fish but would not suggest it. You would be doing massive amounts of wcs and your terror will ..... well become a terror. You are eventually gonna have to rehome some cichlids if you get more.
i wouldnt even have a gt in a 55.... 75 MIN for one. besides that you could have the firemout the convict ( same sex or all heck will break lose ) and poss a salvini then add 12 tiger barbs for dither and you good to go