What would've happened if Oakheart hadn't rejected his brother's deputy proposal?
 

If Oakheart had not rejected Crookedstar's deputy position, would the Warriors series be any different? Would Bluestar's decisions as a leader change because of his requests? Would there be much tension between River and Thunder anymore? If he was leader, he wouldn't have died by a rockfall it'd be someone else instead or no one at all. But what's even crazier, would Thunder and River be one clan? Would Rusty still be leader of ThunderClan or whatever merged clan? Honestly, i think he rejected the deputy position for plot convinces by the Erins and it really would've changed the series if accepted it.

Re: What would've happened if Oakheart hadn't rejected his brother's deputy proposal?
 

I don't think anything would've really changed. Oakheart was Crookedstar's first choice, and when he rejected the proposal, it just made Timberfur deputy until he resigned (or died, since neither have been confirmed.)

Other than getting the rank a bit sooner and reducing the amount of deputies RiverClan had, I highly doubt anything noteworthy would have changed within the series. The Erins would have still had him get squished by a rock and Crookedstar would have still died of Greencough at the end of A Dangerous Path.

All in all, there was never anything particularly significant about Oakheart being deputy of RiverClan. He didn't do a lot besides participate in battles and (as a warrior) took on a mate in another Clan. Their relationship by then was already shattered and their loyalties were to their own Clan. Tensions would've remained the same.

Realistically, you could just take Oakheart out of the books entirely and overall, not much would change other than the removal of a few half-Clan cats and changes within the high ranks. It's likely Leopardstar wouldn't have felt any remorse at all for killing the half-Clan cats because there wouldn't be anyone to protect Stormfur and Feathertail.

Re: What would've happened if Oakheart hadn't rejected his brother's deputy proposal?