If I had the ability to focus and any writing talent I would write a Warriors AU where Fireheart has a small crush on Graystripe, but Graystripe is unfortunately very straight and in love with Silverstream.
But when Graystripe is in RiverClan, Longtail falls for Fireheart, eventually LongFireSand happens, and Longtail is made deputy after Whitestorm dies. Graystripe and Firestar are still best friends but Graystripe has shown that his loyalty is spotty and never really trained his apprentice so...
Longtail still gets blinded and retires, and THIS is when Graystripe is named deputy (he will have trained another apprentice at this point).
Fast forward to Power of Three, after Jayfeather is no longer a 6 moon old baby, he realizes he was too hard on Longtail (and Brightheart) and apologizes.