Mannahnin
Scion of Murgen (He/Him)
The Rules Cyclopedia is 1991 and the Complete Fighters Handbook 1989 anyway.Thanks, Moldvay B/X Basic was what I started D&D with and I only got a Mentzer basic boxed set decades later when a friend was downsizing their collection prior to a move, so I am not familiar with its specific unique bits other than the little bits I have flipped through or looked up specifically and this is sort of a tucked away passage.
1983 is well before the 2e era and the 1989 Complete Fighter's Handbook.
A quick scan of my Rules Cyclopedia PDF does not show a similar suggestion there, but it might be similarly tucked away in a non-obvious area.
Mentzer vs Moldvay has all sorts of interesting little tweaks and differences. One I just was reminded of last week was that Mentzer gives you a slightly more explicit definition for what Holmes and Moldvay call "hopeless characters" who should be re-rolled.
Holmes Basic p8 and Moldvay B13:
Compare to Mentzer, B48: