I'd take all the sydontis and one pleco back....and trade for about 5 small corys. ...peppered or Pandas stay under 2-inches approx.
Also, I'm not sure the platies are compatible with an angel. I mean, there's always a chance they'll get along fine, but.....typically, livebearers are food for cichlids. I'd return the platies and get another angel.
Funny, I was wondering why my eupterus was so "small" so my husband and I actually measured it today (I was guesstimating before). It is actually more like 8". So yes, keep eating your ice cream and take those bad boys back.