I already completed set and runewords. I'm at 95% uniques.
Tyrael's is one of the uniques missing.
My advice is: worry about your unique chronicle only after you find Tyrael's.
It is easier to complete all sunders, colossal jewels and torchs than finding Tyrael's.
Some very low level items you have to farm in normal. Kill superuniques in cold plains, tristam, dark wood (coldcrow, bishbop, etc.). Use a barb to hork.
This is your personal experience... some people have found 3 Tyraels and are still missing one of the sunders...