Earlier quoted context omitted.
I don't think your plan is for everyone since if you need to be synced with a team not working on Wednesdays is negative in the long run.
This happens where I work- one of my coworkers is here Monday - Thursday (10 hour days) but takes Friday off. He's the only one with knowledge of a lot of our legacy systems, so a lot of potential work doesn't happen on Fridays. I'd argue that more of us should learn what he knows to avoid "hit by a bus syndrome" but we don't have enough spare man hours to devote to that.
Seriously though, no man should be irreplaceable because of his knowledge, this is some serious risk you are taking.