Its a similar stock to my tank, which is a 240 at the moment but a 125g is coming soon probs at xmas. If it were me I would drop the threadfin and up the cupids/wavereni to 4/5 they do better in groups. Although its upto you if you do that or drop one of the other geos to do more of the cupids as threadfins and cupids are found in the wild naturally and I have heard of them doing well in tanks together but threadfins are often nasty to big geophagus. Also the rio 400 is a 5x2x2 (more a less?) isnt it? If so IMO thats a decent size for Clowns? Although when/if they get to adult size that would perhaps push the tank over the edge stock wise.
One thought though, no dithers? I would maybe add a school of larger tetras in there just to help out anything like lemons, xrays, flame, bleeding hearts or columbians would work well.
Wills