Those are definitely NOT A. erythrura and the A. cacatuoides 'Triple Red' seem to have very small pelvic fins for that size of fish.
There is a little fin burn on the cacatuoides (I'm guessing from shipping) that should grow back out.
The A. trifasciatus are at about 1". What traits are you using to distinguish them as trifasciatus and not erythrura? Color can't be used yet as they are young and no where near full color. I'd like to know what to look for beyond the red tail of adult dominant males. I see pictures of some adult erythrura that show a hint of an angular line through their belly.