I just had an idea how to fix this d*** chief reigns timeline. Oh ... there will still be need to "finesse the dates to fit whatever your personal idea is" - like jeb pointed out. But I might have a logical explanation for this whole "Bearclaw is the eldest elf and longest chief ever" issue.
And it will still be about "forgetfulness" on the Wolfriders' side - a very comprehensible forgetfulness, without blaming just the "Now of Wolf Thought". Give me some time to find the right words to get my idea through.