Ok, here are the probabilities:

Spoiler Alert, click show to read: 

Natural Energy 5 = 15%
Natural Energy 6 = 30%

with the HaleAndHearty trait (In the Pink, etc).
Natural Energy 5 = 30%
Natural Energy 6 = 60%



Ptolemaios has a 15% chance, unless he gets a lot healthier.



They probably need increasing.