I've grown various Cyperus over the years, I have one now that I let totally dry out, all the top leaves died but the crown survived. 2-3 months later it's now just putting out leaves.
So in my experience the Cyperus are pretty indestructible.
The browning leaves may even be from earlier drying out. Just give it regular water and not too much fertilizer and it'll grown fine. You could just cut off the dying leaves and stems.
Hydrocotyle, it grows like a weed, just give it time.
as for other members.. maybe they're on vacation...they'll be back.