my headcanon for a long time has been that souls have a degree of control over when/where/how they're reborn. that's why the same souls keep returning to the Dotharl tribe: they choose to.
it also provides a logical explanation for some people (Gerolt, Rowena, the trolley crew) looking exactly the same across reincarnations despite one side of my brain screaming that that doesn't make any sense with either real life genetics or how even in game, people end up looking more or less like their family members. perhaps souls have a preferred form that, within limits, they can facilitate being reborn as.
(the soul having some role in determining physical form would also dovetail with dragons' system of asexual reproduction and personal evolution; despite them being from a different star, they still ought to operate under the same natural laws)
at the same time, the key would be that it is a choice — and that allows the WoL to be anything. you don't have to look like Ardbert, because why wouldn't Azem, the traveler, counselor to the people, want to be someone different, live somewhere different, have totally new experiences, in every new life?
