I have never kept godmanni, but have kept intermedia a couple times, and still have fry from the 2nd group.
First time was this variant
and in the last couple years, this one.
And yes, they have been lumped in with Vieja in the past, but were first described in 1862 as Heros, then reassigned to Chuco by Kullander in 1983, when he disassembled Cichlasoma (another genus they had been lumped in).
I have not found them to be overly aggressive, but hold their own, and not quite as vegetarian as Vieja tend to be, but more on the omnivorous side.
As of now, I have the young micropthalmus with the Madagascan cichlid Ptychochromis sp Tarantsy.