I would put Ajantis in the 22-24 range, Anomen in the 24-26 range, and Keldorn in his early 40s.
Ajantis acts like a young firebrand who has not really seen all that much of life. His rigid fanatacism (and I mean that in the best possible sense) has not been tempered by experience or disappointment. The process of aging will probably mellow him a bit.
Anomen is also youthful, and Keldorn certainly treats him as if he's still a schoolboy, but both of them seem to act as if he's really a bit too old to need this instruction. He does show flashes of wisdom, but he also shows great gulfs of ignorance and prejudice. I adore Anomen, but he is what he is.
I've got an argument for my impression of Keldorn's age
here, though there are plenty of people who disagree. Either Maria is still young enough to bear children or Keldorn is woefully confused about biology (he asks Sir William if he intends to father a child with her). Either is possible, but it always seemed to me as if Keldorn and Maria were about the same age. I would expect more deference from a child bride toward her older husband, even if 20 years had passed since they were married, but she treats him with absolute equality of status. To me, that suggests that she's in the 36-42 neighborhood, too, and his contemporary. Though Keldorn must be over 40, by his own admission. I felt it safest never to declare absolutely how old he was.