I wonder if this is perhaps a pointless argument. Surely if Pérez or another driver joined Alonso at Ferrari, it wouldn't be on an equal footing: wouldn't there be a clause in his contract enshrining Fernando's precedence?
Effectively but I think Massa said after Germany 2010 that the driver contracts were the same and committed them both to obeying team orders. Ferrari's driver plan is widely believed to have included Kubica alongside Alonso. I know they're good friends but I couldn't see the pre-accident Kubica accepting a drive that focused all his efforts on his team mate. Also, if Raikkonen's contract had stipulated direct favouritism then Ferrari would have breached it in 2008. I don't reckon Ferrari offer Schumacher-style contracts any more or that his post-2006 terms and conditions were likely to have been renewed unchanged, which is why he left. If a driver did come in and beat Alonso I don't think the contracts would prevent Ferrari ordering Alonso to support him.