The premise of this thread is weird. Both Sid & Ovechkin should and will have their numbers retired pretty damn quickly. The only way Sid's number is in the rafters a meaningful amount of time before Ovechkin's is if Ovi decides to continue playing in Russia after retiring from the NHL and the schedules don't allow him to actually be in Washington for a ceremony. There are a lot of reasons Jagr had to wait a good while that won't apply to Ovechkin, even if he just keeps playing in perpetuity. The fact the Penguins were able to get Jagr over in the middle of the season for his means the Caps may not even wait until he's finished in Russia, so long as there's a break that allows him to be in Washington for it.
Honestly I really hope they both get their numbers retired within the same week...that'd be so special and appropriate. No need to hold it up if one retires before the other, but if they go out at the same time it'd just be cool. At the end of the day these guys both clinched their number retirements a long, long, long time ago and nobody is wearing those numbers for their respective franchises again, even if it's not immediately retired. Michel Briere was the last Penguin to wear #21, even if it took 30 years for it to be officially retired.