I once again have to kindly disagree.
Looks like people once again can not distinguish between damage tolerance and damage endurance.
The Hippo is a damage tolerant design - all those easy to replace and non-essential support systems make it capable of taking a lot of damage.
If you heavily armored it, it would need a lot bigger engines, would have a lot less space for medical stuff and wouldn't be so effective as a mobile hospital.
As is, it *will* get hurt in a fight. However it will only be *hurt*, not *crippled*. Granted all that blown away superstructure will be hard on the eyes, but it has more than enough redundancy to still be operational...
getting rid of all the big and heavy support beams and girders that a heavy armor and a huge engine block would have required makes it possible to make the ship fast and cheap.
Just because the frame and superstructure of the ship is less armored doesn't mean, that the parts actually housing the patients aren't. In fact, that's where all the any real armor is on the ship and it's a lot thicker than what you find on some cruisers.
....
Bottom Line: Leave the ship as is. You can't please everyone, and so far many people liked this design.