Lenticulata Pike Cichlid Mates?

[Scatocephalus]

How big would say is "large enough"?

Also, I see some motoros in your pic but noticed you didn't include them in your list. Did that combo not work out?

The tank pictured is a 125 which is the smallest I'd even consider with lugubris pikes.

The pikes tended to pick at the edge of the rays' disc. Not out of aggression, just curiosity. The rays quite often had small wounds and notches missing from them.