Back in the day that was an issue, but not anymore (as long the drives are ofc from the same array). You might get some problems registered in the Storage Manager about the needed fix on the systems partition, but that will be a simple click and a few second fix.
Just to update, I had an issue, restarting kept giving me an issue saying pool was corrupt,blah blah blah. It didn't like them all in on power up... said many had system partition issues.
So I pulled the drives and inserted them 1 by 1, which it liked no partition errors and each registered as healthy, except 1 (drive 3) said crashed - though it did say healthy but crashed, even ran a smart test with no errors, but would not repair. I had to disconnect 3 from the pool from the drop down menu, and reinstall it, which formatted it after warning me it would do so, and it started to rebuild the raid pool...its still going, it rebuilt in a few hours, now its data scrubbing.... but it shows everything as good.
#3 showed healthy, but crashed..? I know it all started because they all got put in and powered on, in a jumbled order or at least not the original slot order. But at least its fixing it with no data loss... I would have hated to re-backup all that, it took 3-4 days last time I think?
Moral to this story for anyone reading in the future, try inserting them 1 at a time while the unit is on, and hopefully it will all come back to life.