Do you sometimes think about this quote from PLatRoA:
I mean this is already a strong statement if you view it out of context but once you realize that it's Derek, a Replimoid, who immediately saw Marius and Lestat as father and son… as soon as you realize how these Replimoids procreate… this becomes an even stronger statement. When Derek says it, it really hits differently.
And then there's another layer which gets unpacked as you think of Derek and Dertu in particular but I can't put into proper words. Something about both Lestat and Dertu being simpler souls compared to their "fathers", less sensitive/thoughtful but more efficient in emergency situations.
(The second paragraph is just here to show some appreciation towards their different styles. "... as though he'd never slouched or slumped or relaxed in his entire long immortal life..." - somebody plz give this old man a beanbag chair and a head massage OK?)